Nine compounds containing high-nuclearity [Cu_nX_2n+2]^2- (n = 4, 5 or 7; X = Cl or Br) quasi-planar oligomers

The structures of seven A₂Cu₄X₁₀ compounds containing quasi-planar oligomers are reported: bis­(1,2,4-trimethyl­pyridin­ium) hexa-[mu]-chlorido-tetra­chlorido­tetra­cuprate(II), (C₈H₁₂N)₂[Cu₄Cl₁₀], (I), and the hexa-[mu]-bromido-tetra­bromido­tetra­cuprate(II) salts of 1,2,4-trimethyl­pyridinium, (C₈H₁₂N)₂[Cu₄Br₁₀], (II), 3,4-dimethyl­pyridinium, (C₇H₁₀N)₂[Cu₄Br₁₀], (III), 2,3-dimethyl­pyridinium, (C₇H₁₀N)₂[Cu₄Br₁₀], (IV), 1-methyl­pyridinium, (C₆H₈N)₂[Cu₄Br₁₀], (V), trimethyl­phenyl­ammonium, (C₉H₁₄N)₂[Cu₄Br₁₀], (VI), and 2,4-di­methyl­pyridinium, (C₇H₁₀N)₂[Cu₄Br₁₀], (VII). The first four are isomorphous and contain stacks of tetra­copper oligomers aggregated through semicoordinate Cu...X bond formation in a 4(,) stacking pattern. The 1-methyl­pyridinium salt also contains oligomers stacked in a 4(,) pattern, but is isomorphous with the known chloride analog instead. The trimethyl­phenyl­ammonium salt contains stacks of oligomers arranged in a 4(,) stacking pattern similar to the tetra­methyl­phosphonium analog. These six structures feature inversion-related organic cation pairs and hybrid oligomer/organic cation layers derived from the parent CuX₂ structure. The 2,4-dimethyl­pyridinium salt is isomorphous with the known (2-amino-4-methyl­pyridinium)₂Cu₄Cl₁₀ structure, in which isolated stacks of organic cations and of oligomers in a 4(,) pattern are found. In bis­(3-chloro-1-methyl­pyridinium) octa-[mu]-bromido-tetra­bromido­penta­cuprate(II), (C₆H₇ClN)[Cu₅Br₁₂], (VIII), containing the first reported fully halogen­ated quasi-planar penta­copper oligomer, the oligomers stack in a 5(,) stacking pattern as the highest nuclearity [Cu_nX_2n+2]^2- oligomer compound known with isolated stacking. Bis(2-chloro-1-methyl­pyridinium) dodeca-[mu]-bromido-tetra­bromido­hepta­cuprate(II), (C₆H₇ClN)₂[Cu₇Br₁₆], (IX), contains the second hepta­copper oligomer reported and consists of layers of inter­leaved oligomer stacks with a 7[(,)][(-,-)] pattern isomorphous with that of the known 1,2-dimethyl­pyridinium analog. All the oligomers reported here are inversion symmetric.

S1. Comment

Linear Cu_nX_2n+2^2- oligomers (X = Cl, Br) exhibit a wide range of structural variation. Among the simplest are isolated dicopper oligomers formed by edge-sharing CuX₄ flattened tetrahedra. More complicated structures are formed when oligomers aggregate into stacks, in which copper(II) ions from one oligomer form long semicoordinate bonds to halide ions in neighboring oligomers. Here, edge-sharing distorted CuX₄ square planes yield quasi-planar oligomers that stack with a plethora of arrangements (Bond & Willett, 1989). The simplest stacking has translationally equivalent oligomers, but ranges in complexity from the five-oligomer repeat sequence observed in (4-methylpyridinium)₂Cu₃Br₈ (Bond, Willett & Rubenaker, 1990). To represent oligomer stacking, Geiser, Willett et al. (1986) developed simple envelope diagrams and a distinctive notation. A rectangular envelope represents the oligomer, with diagonal lines inside for the trans X—Cu—X bonds of the CuX₄ squares, which ideally meet the edges and corners at the ligand positions and intersect at the Cu²⁺ positions. The envelopes are stacked offset so that some, or all, of the Cu²⁺ ions of one oligomer sit above or below the halide ions of the neighbors. The corresponding notation starts with a number denoting the nuclearity of the oligomer. Following this, in parentheses, are length measurements (as fractional multiples of the CuX₄ edge length) that describe how far the neighboring oligomer is offse, first parallel and then perpendicular to the long axis of the oligomer. As many offset measurements are appended as are needed to establish the repeat unit of the stack. If an oligomer is a member of two different interleaved stacks, the pattern for each individual stack is enclosed in square brackets. Weise & Willett (1993) have shown that the various stacking patterns can be derived from the layer structure of CuCl₂ or CuBr₂ by terminating sections of the layers with additional halide ions (accompanied by counterions) and also, for more complicated patterns, including stacking faults. Envelope diagrams and their stacking notations for structures reported in this paper are presented in Fig. 1.

The first, prototypical, oligomer compounds were LiCuCl₃.2H₂O (Vossos et al., 1960, 1963), but more particularly K₂Cu₂Cl₆ and (NH₄)₂Cu₂Cl₆ (Willett et al., 1963), in which H₂O is not semi-coordinated to the Cu₂Cl₆^2- complex. A survey of the Cambridge Structural Database (CSD, Version?; Allen, 2002) shows approximately 20 such dicopper oligomer compounds have since been discovered, and at least ten similar compounds with neutral N- or O- donors for up to two terminal ligands. (Isolated dicopper oligomers, composed of edge-sharing flattened tetrahedra, have approximately 40 compounds known). Oligomer compounds of the form A₂Cu₃X₈, with at least ten known examples, are less common. Examples are more rare as nuclearity increases. Seven A₂Cu₄X₁₀ oligomer compounds have been reported to date: [(CH₃)₃NH]₂Cu₄X₁₀ [X = Cl, Caputo et al. (1976), CSD refcode MEAMCU10, stacking pattern 4(3/2,1/2); X = Br, Geiser, Willett et al. (1986), CIVNAW10, 4(3/2,1/2)(1/2,-1/2)], (2-amino-4-methylpyridinium)₂Cu₄Cl₁₀ [Halvorson et al. (1987), FIRWEI, 4(1/2,1/2)], [(CH₃)₄N]₂Cu₄Cl₁₀ [Halvorson et al. (1987), FIRWIM, 4(3/2,1/2)], [(CH₃)₄P]₂Cu₄Br₁₀ [Murray & Willett (1991), VOGROY, 4(3/2,1/2)], (1-methylpyridinium)₂Cu₄Cl₁₀ [Bond et al. (1995), ZACSEB, 4(5/2,1/2)] and (2-chloro-4-methylanilinium)₂Cu₄Cl₁₀ [Fu & Chivers (2006), GEJTEV, 4(3/2,1/2)]. Pentanuclear Cu₅Cl₁₀(i-PrOH)₂ [Willett & Rundle (1964), PCUCPR, 5(3/2,1/2); redetermined by Pon & Willett (1996), PCUCPR02] was for many years the highest nuclearity oligomer known. Here, the oligomer stacks are not isolated but are linked to neighboring stacks through semicoordinate bond formation to generate a herringbone pattern, an arrangement also found in GEJTEV. The hexanuclear oligomer compound, (1,2-dimethylpyridinium)₂Cu₆Cl₁₄, was first reported by Zhou et al. (1988) {ZACSIF, 6[(5/2,1/2)][(-9/2,-1/2)]}, with full structural details of this and the related heptanuclear oligomer compound, (1,2-dimethylpyridinium)₂Cu₇Br₁₆ {ZACSOL, 7[(7/2,1/2)][(-9/2,-1/2)]}, provided by Bond et al. (1995). These hexa- and heptanuclear compounds contain interdigitated, rather than isolated, stacks of oligomers. A second hexanuclear oligomer compound, (n-C₃H₇NH₃)₂Cu₆Cl₁₄ [Fu & Chivers (2006), GEJTAR, 6(3/2,1/2)], obtained through solvothermal synthesis, contains neighboring oligomer stacks in the herringbone arrangement of PCUCPR, rather than the interdigitated stacks of ZACSIF and ZACSOL. The discovery by Haddad et al. (2003) of (3,5-dibromopyridinium)₂Cu₁₀Br₂₂ {UJODUS, 10[(7/2,1/2)][(-15/2,1/2)]}, containing decacopper oligomers in interdigitated stacks, has dramatically increased known oligomer nuclearity.

During the course of our work on copper(II) halide structural chemistry, we have accumulated several new compounds containing high nuclearity Cu_nX_2n+2^2- oligomers with inversion symmetry. These include seven new compounds containing tetracopper oligomers: bis(1,2,4-trimethylpyridinium) hexa-µ₂-chlorido-tetrachloridotetracuprate(II), (I), and the hexa-µ₂-bromido-tetrabromidotetracuprate(II) salts of 1,2,4-trimethylpyridinium, (II), 3.4-dimethylpyridinium, (III), 2,3-dimethylpyridinium, (IV), 1-methylpyridinium, (V), trimethylphenylammonium, (VI), and 2,4-dimethylpyridinium, (VII). In addition, we present the second reported examples of a pentanuclear oligomer compound, bis(3-chloro-1-methylpyridinium) octa-µ₂-bromido-tetrabromidopentacuprate(II), (VIII), and a heptanuclear oligomer compound, bis(2-chloro-1-methylpyridinium) dodeca-µ₂-bromido-tetrabromidoheptacuprate(II), (IX).

The structures of (I)–(IV) are isomorphous. All crystallize in the monoclinic space group P2₁/n with similar unit cell constants, and contain translationally equivalent quasi-planar Cu₄X₁₀^2- oligomers stacked along a in a 4(5/2,1/2) pattern. Compound (V) is isomorphous with the previously reported chloride analog (ZACSEB), and it bears similarities to, but is not isomorphous with, the structures of (I)–(IV). While (V) does crystallize in the monoclinic space group P2₁/n with an oligomer stacking pattern of 4(5/2,1/2), in this case the translationally equivalent oligomers stack along the monoclinic (b) axis. The central Cu²⁺ ion (Cu1) is square-pyramidal, with four neighboring halide ions within the oligomer forming the basal ligands while the longer Cu—X5 bond to a terminal halide of a neighboring oligomer is apical. The apical ligand induces pyramidalization of the basal ligands, as shown by one trans X—Cu1—X angle in the range 161–163° and the other in the range 167–170° for (I)–(IV). The most acute trans X—Cu1—X angle is exhibited in (V), which also has the largest difference in trans X—Cu1—X angles [158.82 (4) versus 170.73 (3)°]. The terminal Cu²⁺ ion (Cu2) forms a longer (~3 Å) semicoordinate bond to bridging halide X3 of the neighboring oligomer. The more distant apical ligand results in less pyramidalization about Cu2: the X2—Cu2—X5 angle is almost linear (173–175°), while the X3—Cu2—X4 angle (involving the terminal halide ion X4) is more bent (164–168°) for (I)–(V), to give the folded 4+1 coordination environment described previously for ZACSEB. Figs. 2–6 present displacement ellipsoid plots of the organic cation and oligomer for compounds (I)–(V), respectively, and Tables 1–3, 5 and 7, respectively, present geometric parameters for these oligomers. Tables 4 and 6 present hydrogen-bond geometries for (III) and (IV), respectively. A packing diagram for (I) is presented in Fig. 7 and is also representative of (II)–(IV).

The oligomer planes are substantially tilted relative to the stacking axis, forming stacking angles of 66.87 (1), 66.54 (1), 70.01 (1), 68.30 (1) and 65.51 (1)° between their mean-plane normals and the stacking axes for (I)–(V), respectively. These values are all lower than the ideal value of 74.499° found for 4(5/2,1/2) stacking with Cu—X bonds of the same length and X—Cu—X and Cu—X—Cu angles of 90 or 180°. Longer semicoordinate bonds between oligomers tend to decrease the stacking angle by further separating the oligomers. On the other hand, outer X—Cu—X and bridging Cu—X—Cu angles greater than 90° [90–94° and 93–95°, respectively, for (I)–(V)] result from lengthening of the oligomer and tend to increase the stacking angle. The stacking angle is also increased by stretching of the oligomer stacks along the stacking axis, as evidenced by outer angles between the basal and apical ligands greater than the inner angles for square-pyramidal Cu1. Since the stacking angle is smaller than the ideal, semicoordinate bond lengthening is clearly the strongest factor in deviations from it.

The organic cations form stacks of inversion-related facing pairs between parallel oligomer stacks. The organic cation planes are almost coplanar with the oligomer planes of a given stack, forming angles of 15.43 (4), 12.20 (7), 8.0 (1), 3.8 (3) and 8.6 (1)° between the normals of the mean planes for (I)–(V), respectively, and are located at the ends of the oligomers to provide charge compensation for the terminal halides. Each cation of the pair terminates a different oligomer in translationally equivalent stacks, along b for (I)–(IV) and along a for (V). The organic ring also sits above part of the neighboring oligomer it faces, to block further coordination of Cu²⁺. This structural feature was first noted in ZACSEB and attributed to the presence of the quaternary 1-methylpyridinium cation. In the absence of hydrogen bonding, it was thought that optimizing the out-of-plane electrostatic attraction between the quaternary N atom and a halide ion in a facing oligomer would be the dominant factor in this positioning of the organic ring. A short out-of-plane N···X contact distance [N1···Cl2ⁱ = 3.404 (2) Å in (I), N1···Br2 = 3.578 (5) Å in (II) and N1···Br2 = 3.575 (4) Å in (V); symmetry code: (i) 1 - x, y, z] is also found for the quaternary pyridinium cation in (I), (II) and (V). However, in (III), where hydrogen bonding is present, a comparable contact [N1···Br1ⁱⁱ = 3.672 (7) Å; symmetry code: (ii) 1 - x, 1 - y, 2 - z] is found as well. The cation in (IV) has its N atom placed above the midpoint between two bridging bromide ions to form two simultaneous, but longer, interactions [N1···Br2ⁱⁱⁱ = 4.005 (7) Å and N1···Br3ⁱⁱⁱ = 4.071 (8) Å; symmetry code: (iii) x - 1/2, 3/2 - y, z - 1/2]. Here, packing of the methyl groups in a similar manner to that found in (III) places the N atom in this bifurcated arrangement and directs the hydrogen bond to an oligomer in a neighboring stack. So the out-of-plane interaction between a pyridinium cation and the planar oligomer can be more generally applied beyond the quaternary pyridinium cation for which it was first noted.

The organic cations also form inversion-related end-to-end pairs with a very small interplanar spacing [0.431 (7), 0.562 (15), 0.850 (20), 0.435 (23) and 0.455 (14) Å for (I)–(V), respectively] that involve cations of neighboring facing pairs. These end-to-end cation pairs abut approximately coplanar oligomers, and vice versa, to establish hybrid organic cation/oligomer ribbons through the structure. The ribbons stack to form layers in the ab plane, so that the ribbon planes are parallel to (130) or (130) in alternating layers [(310) or (310) for (V)]. The interplanar spacing between organic cations in the facing pair [3.498 (3), 3.681 (6), 3.612 (8), 3.544 (12) and 3.478 (6) Å for (I)–(V), respectively] is not dramatically longer than the typical Cu—X semicoordinate bond distance. So the facing cation pairs easily fit together with the oligomer stacks to establish a hybrid organic cation/oligomer layer structure in the ab plane, reminiscent of the layered CdI₂-type structures of CuCl₂ or CuBr₂. Such a description has been used for for a series of structures, e.g. [(CH₃CH₂)₃NCH₃]Cu₃Cl₇ (LABXEC), in which holes in the CuX₂ layer structure produced by the absence of a Cu_nX_2n-2²⁺ fragment are occupied by pairs of organic monocations (Weise & Willett, 1993). The [(CH₃CH₂)₄N]₂Cu₅Cl₁₂ structure (ZOKCEH), in particular, features holes produced by the removal of Cu₄Cl₆²⁺ fragments to leave parallel stacks of Cu₄Cl₁₀^2- oligomers in a 4(5/2,1/2) pattern, linked to one another by CuCl₄ square planes (Ayllón et al., 1996). Removing the linking complexes, now by removing Cu₅X₈²⁺ fragments, leaves isolated stacks of 4(5/2,1/2) oligomers. Placing facing organic cation pairs in these holes would then give the layer structures of (I)–(V). In fact, the smallest fragment removed from the CuX₂ layer that produces isolated 4(5/2,1/2) stacked oligomers is planar Cu₃X₄²⁺, as illustrated in Fig. 8. Holes of arbitrarily large size can be produced by adding an appropriate number of CuCl₂ units to this smallest fragment. Thus, the layer structures of (I)–(V) may be considered as either cation pairs occupying holes in the CuX₂ layer left by removal of Cu₃X₄²⁺ fragments with expansion of the layer to accomodate the cations, or as cation pairs occupying holes in the CuX₂ layer produced by removal of larger fragments that match the cation pair size. Oligomer stacks in neighboring layers are then arranged to be directly adjacent to cation pair stacks, and vice versa.

The aromatic rings are arranged so that the methyl groups in (III)–(V) are located within the organic cation stack, with the long cation axis approximately parallel to the long oligomer axis. In (I) and (II), however, the long axis of the cation is approximately perpendicular to the long axis of the oligomer it terminates. With methyl groups on opposite sides of the aromatic ring, the organic cation in (I) and (II) is longer than those in (III)–(V). To align the long axis of this cation parallel to the long axis of the oligomer would likely force a longer translation between neighboring oligomers in the stack to produce a 4(7/2,1/2) stacking pattern. This stacking pattern allows only half of the Cu²⁺ ions of the oligomer to form semicoordinate bonds, unlike the 4(5/2,1/2) pattern which allows every Cu²⁺ ion to form one semicoordinate bond. While the 4(7/2,1/2) pattern has yet to be observed, the 4(5/2,1/2) pattern is (to date) the most frequently observed A₂Cu₄X₁₀ pattern, accounting for six out of the 14 reported structures. This pattern appears to balance successfully semicoordinate bond formation by the Cu²⁺ ions against close assocation of the planar organic cations with the oligomers.

The structure of the trimethylphenylammonium salt, (VI), consists of both translationally equivalent tetracopper oligomers in a 4(3/2, 1/2) pattern and inversion-related facing organic cation pairs stacked parallel to a. The central Cu²⁺ ion (Cu1) is 4+1+1' coordinated, with a semicoordinate bond to terminal bromide ion Br4 and a longer bond to bridging bromide ion Br2 of opposite neighboring oligomers. The terminal Cu²⁺ ion (Cu2) is 4+1 coordinated, with a semicoordinate bond to bridging bromide ion Br1 of a neighboring oligomer. For Cu1, the longer semicoordinate ligand is too distant [3.5416 (7) Å] to influence the coordinate ligand geometry substantially, so both Cu²⁺ ions show significant pyramidalization of the coordinate bromide ions, with trans Br—Cu—Br angles in the range 167–173°. A displacement ellipsoid plot of the organic cation and oligomer is presented in Fig. 9, with a packing diagram for the structure presented in Fig. 10. Table 8 lists geometric parameters for the oligomer.

The organic cations and oligomers {of (VI)?] are both tilted relative to a, with the long axis of the cation (as defined by the N1···C4 line) forming an angle of 50.96 (9)° and the oligomer plane normal forming an angle of 61.164 (4)° (less than the ideal value of 65.905°) with respect to a. The facing pair of organic cations are offset, so that only atom C4 of each ring sits above that of the other ring, with an interplanar spacing between the phenyl rings of 3.376 (7) Å. Each cation is also related by inversion to a cation in a neighboring pair. Here, the two rings are far more offset from one another, with the closest contact of 2.36 Å occurring between H4 atoms. The large offset of these cations precludes any overlap of the phenyl rings and permits a smaller interplanar spacing of 1.471 (11) Å. Organic cation pair stacking is also found in the structure of (trimethylphenylammonium)₂Cu₃Cl₈ (Bond, 2010). In that case, the cation pairs form a longer repeat distance [7.4496 (1) Å, versus 6.3969 (1) Å in (VI)] due to closer pairing. Indeed, organic cation repeat distances of 6.1–6.4 Å for (VI), FIRWIM and VOGROY match the repeat distances for other isolated tetramethylammonium cation stacks, for example in [(CH₃)₄N]NiX₃ [X = Cl (TMANIC) or Br (TMABNI10); Stucky, 1968]. Thus, the repeat distance in (VI) is consistent with the packing of the trimethylammonium head group. For (trimethylphenylammonium)₂Cu₃Cl₈, the organic cations assume a preferential packing mode which enforces a repeat distance on the chloridocuprate(II) chain that leads to an unusual chain structure. With the larger bromide ion present and a higher ratio of Cu²⁺ to organic cation in (VI), the inorganic portion of the structure now plays a stronger role in defining the packing to produce the more offset cation pairing. The trimethylammonium head group of the cation is directed towards the end of the Cu₄Br₁₀^2- oligomer, with the phenyl ring directed away from the oligomer. Similar termination of the oligomer by (CH₃)₄Pn⁺ (Pn = N or P) is found for FIRWIM and VOGROY. The interaction between the cation and the oligomer is far less specific here than the out-of-plane interaction that generates the longer 4(5/2,1/2) stacking translation found for compounds (I)–(V). In this case, the intermediate-length parallel translation of the 4(3/2,1/2) pattern could arise simply from the need for the oligomer stacking to match the repeat distance dictated by packing of the trimethylammonium head group. Indeed, the structure of the trimethylammonium chloride salt (MEAMCU10) is also isomorphous with FIRWIM, even though the organic cation/oligomer interaction is a specific hydrogen bond that orients the head group away from the oligomer.

The triclinic unit cell of (VI) is not isomorphous with FIRWIM or VOGROY, which crystallize in the monoclinic space group P2₁/c. An obvious difference between these structures, then, is that all oligomer stacks in (VI) are translationally equivalent. However, the values for b and c in (VI) are similar, as are the values for β and γ, which suggests a transformation using the matrix (100,011,011) to a nominal C-centered unit cell with (approximately) monoclinic cell constants: a' = 6.3969 (1) Å, b' = 14.2740 (3) Å, c' = 19.4957 (3) Å, α' = 88.025 (2)°, β' = 90.046 (1)° and γ' = 108.418 (1)° [compared with a = 6.425 (2) Å, b = 20.379 (6) Å, c = 11.243 (3) Å and β = 98.52 (2)° for VOGROY]. [The transformed b' axis is significantly longer than the corresponding axis (c) in VOGROY because it aligns closely to the long axis of the trimethylphenylammonium cation.] In spite of the geometric similarities between these structures, (VI) is distinctly different. The oligomer stacks and organic cation pairs form layers parallel to [012] that are reminiscent of CuBr₂ layers. In this case, the layers can be conceived as inserting organic cation pairs in to holes formed by removing planar Cu₂Br₂²⁺ fragments (as shown in Fig. 11). Layers are arranged as in (I)–(V) so as to sandwich cation pair stacks with oligomer stacks and vice versa. This layer description is not, however, apparent for the (CH₃)₄Pn⁺ salts, where distinct organic cation pairing is not present and the oligomer stacks are canted with respect to any possible layer plane.

A₂Cu₄X₁₀ structures for other variations of the tetramethylammonium cation have not been identified. The simplest variation would be ethyltrimethylammonium, for which a [Cu₅Cl₁₄^4-]_n chain structure is known (Bond, Willett et al., 1990), but it appears that no attempt has been made to prepare Cu₄X₁₀^2- salts. Based on the structures of (V), FIRWIM, VOGROY and MEAMCU10, a 4(3/2,1/2) oligomer pattern would be expected for such a salt as well. Oligomer structures are known for more highly substituted tetramethylammonium cations. Both diethyldimethyl- (Willett, 1991) and tetraethylammonium (Willett & Geiser, 1986) form compounds with Cu₄Cl₁₂^4- oligomers, and triethylmethylammonium forms a Cu₃Cl₉^3- oligomer compound (Willett, 1991). In these structures the bulkiness of the organic cations, and the higher ratio of organic cations to Cu²⁺ ions, prevents aggregation of the oligomers and they are isolated. Likewise, [(CH₃)₄P]₂Cu₄Cl₁₀ (Haije et al., 1986; FAMYIB) and [(CH₃)₄As]₂Cu₄Cl₁₀ (Murray & Willett, 1993; LATRON) both occur as complicated layer structures with holes occupied by pairs of organic cations, rather than as stacks of Cu₄Cl₁₀^2- oligomers. Thus, organic cation size is a key factor in determining whether quasi-planar oligomers will be formed in this family. In this regard, Geiser, Gaura et al. (1986) have invoked the organic cation to halide ion size ratio to account for the difference in stacking patterns between (trimethylammonium)₂Cu₄Cl₁₀ and (trimethylammonium)₂Cu₄Br₁₀.

The (2,4-dimethylpyridinium)₂Cu₄Br₁₀ structure, (VII), is isomorphous with that of (2-amino-4-methylpyridinium)₂Cu₄Cl₁₀ (FIRWEI). The unit-cell constants are all larger than for FIRWEI, an obvious result of substituting bromide for chloride. Otherwise the two structures are quite similar. Translationally equivalent organic cations stack parallel to a, and are isolated and parallel to translationally equivalent oligomers that stack in a 4(1/2,1/2) pattern. All Cu²⁺ ions are 4+1+1' coordinated, with semicoordinate bond lengths >3 Å. Longer semicoordinate bonds lead to weaker distortions from planarity of the coordinate ligands than are observed in (I)–(VI). There is no overlap between the organic ring and the oligomer plane, resulting in the minimum parallel translation of neighboring oligomers within the stack. The oligomer mean plane is less tilted relative to the stacking axis than those in (I)–(VI), the normal forming an angle of 37.842 (6)° with a, less than the ideal value of exactly 45°. The organic cations are located at the ends of the oligomers to provide charge compensation for the terminal bromide ions, similar to the arrangements between the organic cations and oligomers found in (I)–(VI). The organic cation is strongly tilted relative to the oligomer in this structure, though, with an angle of 19.4 (2)° between mean plane normals. The hydrogen bonding between the organic cation and the oligomer is much weaker than in (III) and (IV), with H···Br distances approaching 3 Å. Other than providing charge balance in the crystal structure, the organic cations appear to have little interaction with the oligomer. The interplanar spacing between neighboring organic cations in the same stack is 3.751 (7) Å, greater than the sum of the van der Waals radii for two C atoms (Standard reference?) and larger than the interplanar spacing between pairs of pyridinium cations in (I)–(V). Thus, there appears to be little or no π–π interaction between neighboring organic cations in the stack. A displacement ellipsoid plot of the organic cation and oligomer is presented in Fig. 10, with geometric parameters for the oligomer presented in Table 9 and hydrogen-bonding parameters in Table 10.

One might first expect (VII) to have a structure similar to that of the closely related pyridinium cations in (I)–(IV). It is also surprising, given the strong effect that hydrogen bonding has been found to have in halidocuprate(II) structures (Geiser, Gaura et al. 1986), that replacement of the strongly hydrogen-bonding amino group by methyl produces so little structural difference. One similarity between the organic cations in (VII) and FIRWEI is the presence of electron-donating groups, –CH₃ and –NH₂, in the ortho and para positions of the aromatic ring, which, using classical resonance arguments, would both tend to delocalize positive charge away from the N atom. More disperse positive charge would weaken the out-of-plane interaction between the formal charge center of the organic cation and a halide ion in a facing oligomer. Semicoordination to a Cu²⁺ ion of a neighboring oligomer would now be the stronger interaction for the halide ion, thus generating a stacking pattern with the shortest parallel translation and the maximum number of Cu···X semicoordinate bonds. The direct stacking of the organic cations, rather than the formation of inversion-related pairs as in (I)–(V), provides some evidence of this charge delocalization, since it places the formal seats of positive charge (N1) in each cation directly above one another in a position that potentially maximizes their repulsion. The 2,3- and 3,4-dimethylpridinium cations possess only one electron-donating group in the ortho or para position, presumably resulting in less delocalization of the positive charge and a stronger out-of-plane interaction that results in the 4(5/2,1/2) stacking. Likewise, methylating the ring N atom, as in (II), should counteract delocalization of the positive charge beyond the neighborhood of the ring N atom. The difference in stacking pattern arising from small differences in methyl-group positions on the aromatic cation ring in (II)–(IV) and (VII) illustrates the subtle interplay of forces that often determines a particular pattern.

The (3-chloro-1-methylpyridinium)₂Cu₅Br₁₂ structure, (VIII), contains isolated stacks of translationally equivalent oligomers and of translationally equivalent organic cations parallel to a. This is the first reported example of a fully halogenated quasi-planar pentacopper oligomer, and the structure demonstrates that isolated stacking can persist in Cu_nX_2n+2^2- oligomers at least to n = 5. The stacking pattern found in (VIII) is 5(3/2,1/2), with the terminal Cu²⁺ atom (Cu3) 4+1 coordinated (the apical bond being to a bridging bromide ion Br1 in a neighboring oligomer), the penultimate Cu²⁺ atom (Cu2) 4+1+1' coordinated (the shorter axial bond being to the terminal bromide ion Br6 and the longer axial bond to the bridging bromide ion Br2 in opposite neighbors), and the central Cu²⁺ atom (Cu1) 4+2 coordinated (the axial bonds being to the bridging bromide ion Br4 in opposite neighbors). The normal to the mean plane of the oligomer forms an angle of 60.188 (1)° relative to the repeat axis, less than the ideal value of 64.761°. The tilt angle of the organic cation is so steep relative to a that the cations might almost as well be described as arranged in head-to-tail lines rather than as stacks. The organic cation is almost coplanar with the oligomer [angle between mean plane normals 1.83 (4)°], and the oligomer and cation planes are arranged close to (103). The cation ring partially overlaps the oligomer plane, with atom N1 sitting almost directly above the terminal bromide ion Br5 [at a distance of 3.555 (3) Å] to generate the 3/2 parallel translation of neighboring oligomers. The partial overlap of the ring can be ascribed to the position of the chloro group, which is directed away from and extends beyond the oligomer, presumably so as to minimize chloride–bromide repulsion. The oligomer stacks themselves are canted relative to one another, so that the CuX₂-derived oligomer/cation pair layer structure is not apparent. This is consistent with the observed trend in previously discussed tetracopper oligomer structures, where inversion-related organic cation pairs correlate to a layer structure whereas stacked translationally equivalent organic cations do not. A displacement ellipsoid plot of the organic cation and oligomer is presented in Fig. 12 and a packing diagram in Fig. 13. Geometric parameters of the oligomer are presented in Table 11.

The (2-chloro-1-methylpyridinium)₂Cu₇Br₁₆ structure, (IX), is isomorphous with ZACSOL, the other reported oligomer compound in which the heptacopper oligomers form interleaved stacks with stacking pattern 7[(7/2,1/2)][(-9/2,-1/2)]. The central (Cu1), penultimate (Cu3) and terminal (Cu4) Cu²⁺ ions are 4+2 coordinated, forming semicoordinate bonds to bromide ions (Br7 for Cu1, Br3 and Br5 for Cu3, and Br1 and Br3 for Cu4) in opposite neighbors. The next innermost Cu²⁺ ion (Cu2) is 4+1+1' coordinated, with the shorter semicoordinate bond being to the terminal bromide ion Br7 and the longer to the bridging bromide ion Br5 in opposite neighbors. A displacement ellipsoid plot of the organic cation and oligomer is presented in Fig. 13, with geometric parameters for the oligomer in Table 12.

The organic cation in ZACSOL, 1,2-dimethylpyridinium, differs from that in (IX) only in an aromatic ring substituent. Hence, the similarity between the structures might be expected, even though the chloro group should interact differently than methyl. It is known that the structures of copper(II) halide compounds can vary dramatically with small changes in organic cation structure, so it is a point of interest that the (Cu₇Br₁₆^2-)_n structure remains essentially the same. An analagous situation is found for (4-chloropyridinium)₂Cu₃Cl₈ (Zordan et al., 2006; PEGSEA) and (4-methylpyridinium)₂Cu₃Cl₈ (Bond, Willett et al., 1990), which also differ chemically in the substitution of chloro for methyl on the aromatic ring. While both contain quasi-planar tricopper oligomers, there are distinct structural differences. PEGSEA is described as being built of mixed cation/anion ribbons, in which the organic cations form bifurcated N—H···Cl₂Cu hydrogen bonds to the terminal chloride ions at both ends of the oligomer. The organic cations, meanwhile, form symmetric C—Cl···Cl—C interactions with one another to form supramolecular dications that complete the ribbon. A similar ribbon motif is found in the methyl analog, although the ribbons are straighter in this case [with a C—C···C angle of 170.9 (3)° (Bond & Reynolds, 2010) versus a C—Cl···Cl angle of 146.9 (2)° in PEGSEA]. This minor difference in the ribbon motif results in major differences between the structures. PEGSEA crystallizes in the triclinic space group P1, while the methyl analog crystallizes in the monoclinic space group C2/c with significant differences in reduced cell parameters. Also, the oligomer stacking in PEGSEA follows a 3(1/2,1/2) pattern, as opposed to the 3(1/2,1/2)(1/2,-1/2) pattern found in the methyl analog. In (IX) and ZACSOL, the positions of the substituent groups in the ortho positions may restrict the formation of these supramolecular interactions and thus result in very little difference in structure. Furthermore, rather than the ribbon motif found for the para-substituted pyrdinium structures, the structural motif in the heptacopper oligomer structures is of alternating organic and inorganic layers. The substituent groups of the ring are contained completely within the organic layer, so that the layer structure can likely accomodate small changes in the organic cation without disrupting the bromidocuprate(II) framework.

Related literature

For related literature, see: Allen (2002); Ayllón et al. (1996); Bond (2010); Bond & Reynolds (2010); Bond & Willett (1989); Bond et al. (1995); Bond, Willett & Rubenaker (1990); Bond, Willett, Rubins, Zhou, Zaspel, Hutton & Drumheller (1990); Caputo et al. (1976); Fu & Chivers (2006); Geiser, Gaura, Willett & West (1986); Geiser, Willett, Lindbeck & Emerson (1986); Haddad et al. (2003); Haije et al. (1986); Halvorson et al. (1987); Ladd & Palmer (1994); Murray & Willett (1991, 1993); Pon & Willett (1996); Stucky (1968); Vossos et al. (1960, 1963); Weise & Willett (1993); Willett (1991); Willett & Geiser (1986); Willett & Rundle (1964); Willett et al. (1963); Zhou et al. (1988); Zordan et al. (2006).

S2. Experimental

For the quaternary ammonium or pyridinium salts, the tertiary amine, pyridine or substituted pyridine (5 ml) was reacted with excess iodomethane. The resulting iodide salt was converted into the chloride or bromide by halide exchange with excess AgX (X = Cl or Br) in aqueous solution. Otherwise, dimethylpyridine (5 ml) was neutralized with excess concentrated HBr. In all cases, the organic cation halide and copper(II) chloride dihydrate or copper(II) bromide were combined in a 1:2 molar ratio in a solution made 6M in HX. Crystals of (I)–(IX) were obtained upon evaporation.

S3. Refinement

With the exception of (I) and (IX) (see below), all H-atom positions were calculated using a riding model, with aromatic C—H = 0.93, methyl C—H = 0.96 and aromatic N—H = 0.86 Å, and with U_iso(H) = 1.2U_eq(C,N) for aromatic ring atoms or 1.5U_eq(C) for methyl atoms. Bond lengths and angles within the organic cations conform to expected values (Ladd & Palmer, 1994). Secondary extinction corrections were refined.

For (I), aromatic H-atom positions and isotropic displacement parameters were refined [Range of C—H and N—H distances?], while methyl H atoms were fixed in a riding model (C—H = 0.96 Å) with refined isotropic displacement parameters.

For (IX), the initial refinement of an ordered model yielded a 2-chloro-1-methylpyridinium cation with anomalously large displacement parameters for atoms N1 and Cl2, anomalously small displacement parameters for atoms C2 and C11, an anomalously short C2—Cl2 bond length and an anomalously long N1—C11 bond length. This suggested static disorder of the organic cation in which the cation is occasionally flipped so that atoms N1 and C2, and C11 and Cl2, change places. A disordered model was refined in which the minor component atoms N1A and C2A were required to occupy the same positions with the same displacement parameters as C2 and N1, respectively, and the N—CH₃ and C—Cl bond lengths were strictly fixed at 1.47 and 1.76 Å, respectively. Anisotropic displacement parameters were refined for the non-H atoms of the ring, but only for the major disorder component of the subsitutents (C11 and Cl2). H-atom positions were calculated using a riding model as described above, except for the minor component of C11 for which no H-atom postions were included. The site occupancy of the major component refined to 0.834 (4).

Computing details

For all compounds, data collection: COLLECT (Nonius, 1998); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO and SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and ORTEPIII (Burnett & Johnson, 1996). Software used to prepare material for publication: Please provide missing information for (I), (II), (III), (V), (VI), (VII), (VIII), (IX); WinGX publication routines (Farrugia, 1999) for (IV).

Figures

	Fig. 1. CunX2n+2^2- quasiplanar oligomer envelope stacking diagrams and their corresponding notation for compounds (I)–(IX).
	Fig. 2. The structure of the organic cation and oligomer of (I), with the atom-labeling scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 3. The structure of the organic cation and oligomer of (II), with the atom-labeling scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 4. The structure of the organic cation and oligomer of (III), with the atom-labeling scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 5. The structure of the organic cation and oligomer of (IV), with the atom-labeling scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 6. The structure of the organic cation and oligomer of (V), with the atom-labeling scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 7. A unit-cell packing diagram for (I), viewed down c, with a vertical and b horizontal, showing the hybrid organic cation/oligomer layer. For clarity, H atoms have been omitted. N and C atoms are drawn as small circles, Cl atoms as medium-sized circles, and Cu atoms as large circles.
	Fig. 8. The CuX2 layer structure, showing the Cu3Cl4^2+ units, highlighted in gray, that leave behind isolated 4(5/2,1/2) stacks when removed.
	Fig. 9. The structure of the organic cation and oligomer of (VI), with the atom-labeling scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 10. A unit-cell packing diagram for (VI), viewed parallel to b, with a vertical and c approximately horizontal, showing the hybrid organic cation pair/oligomer layers in the (102) planes. Oligomer stacks in adjacent layers neighbor cation-pair stacks and vice versa. For clarity, H atoms have been omitted. N and C atoms are drawn as small circles, Br atoms as medium-sized circles, and Cu atoms as large circles.
	Fig. 11. The CuX2 layer structure, showing the Cu2Cl2^2+ units, highlighted in gray, that leave behind isolated 4(3/2,1/2) stacks when removed.
	Fig. 12. The structure of the organic cation and oligomer of (VII), with the atom-labeling scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 13. The structure of the organic cation and oligomer of (VIII), with the atom-labeling scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 14. A unit-cell packing diagram for (VIII), viewed parallel to a and down the organic cation-pair and oligomer stacks, with b vertical and c horizontal. For clarity, H atoms have been omitted. N and Cu atoms are drawn as large circles, and C, Br and Cl atoms as small circles.
	Fig. 15. The structureof the major component of the organic cation and oligomer of (IX), with the atom-labeling scheme. Displacement ellipsoids are drawn at the 50% probability level.

(I) bis(1,2,4-trimethylpyridinium) hexa-µ-chlorido-tetrachloridotetracuprate(II)

Crystal data

(C8H12N)2[Cu4Cl10]	F(000) = 840
Mr = 853.10	Dx = 2.032 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 3927 reflections
a = 9.0022 (2) Å	θ = 2.9–29.1°
b = 11.2121 (4) Å	µ = 3.98 mm^−1
c = 13.8356 (4) Å	T = 100 K
β = 93.016 (2)°	Needle, dark green
V = 1394.54 (7) Å^3	0.20 × 0.09 × 0.06 mm
Z = 2

Data collection

Nonius KappaCCD area-detector diffractometer	3736 independent reflections
Radiation source: fine-focus sealed tube	2991 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.026
Detector resolution: 9 pixels mm^-1	θmax = 29.1°, θmin = 3.9°
CCD rotation images, thick slices scans	h = −12→12
Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997)	k = −15→15
Tmin = 0.469, Tmax = 0.793	l = −18→18
7229 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.032	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.077	w = 1/[σ^2(Fo^2) + (0.0275P)^2 + 2.3115P] where P = (Fo^2 + 2Fc^2)/3
S = 1.09	(Δ/σ)max = 0.001
3736 reflections	Δρmax = 0.62 e Å^−3
170 parameters	Δρmin = −0.68 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0017 (3)

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cu1	0.18084 (3)	0.03063 (3)	0.51532 (2)	0.01483 (10)
Cu2	0.51513 (4)	0.16952 (3)	0.52136 (2)	0.01479 (10)
Cl1	−0.02167 (7)	0.03680 (6)	0.60762 (5)	0.01820 (15)
Cl2	0.31857 (7)	0.14850 (6)	0.62062 (5)	0.01672 (14)
Cl3	0.36555 (7)	0.06208 (6)	0.40990 (5)	0.01671 (14)
Cl5	0.70383 (7)	0.16880 (6)	0.41966 (5)	0.01690 (14)
Cl4	0.61533 (8)	0.30968 (6)	0.61617 (5)	0.02102 (16)
N1	1.0777 (3)	0.3811 (2)	0.58956 (17)	0.0163 (5)
C11	1.0105 (3)	0.3762 (3)	0.6848 (2)	0.0256 (7)
H11A	0.9104	0.3472	0.6767	0.039 (11)*
H11B	1.0099	0.4547	0.7125	0.040 (11)*
H11C	1.0677	0.3237	0.7270	0.023 (9)*
C2	1.2130 (3)	0.4320 (2)	0.5810 (2)	0.0163 (5)
C21	1.2907 (3)	0.4877 (3)	0.6676 (2)	0.0240 (6)
H21A	1.2990	0.4305	0.7192	0.053 (13)*
H21B	1.2348	0.5554	0.6877	0.052 (13)*
H21C	1.3882	0.5130	0.6515	0.061 (14)*
C3	1.2741 (3)	0.4292 (3)	0.4916 (2)	0.0185 (6)
H3	1.360 (4)	0.468 (3)	0.484 (3)	0.026 (9)*
C4	1.2037 (3)	0.3757 (3)	0.4112 (2)	0.0190 (6)
C41	1.2747 (4)	0.3740 (3)	0.3156 (2)	0.0281 (7)
H41A	1.2977	0.4541	0.2970	0.050 (13)*
H41B	1.2073	0.3390	0.2675	0.048 (12)*
H41C	1.3645	0.3278	0.3211	0.062 (14)*
C5	1.0648 (3)	0.3235 (3)	0.4242 (2)	0.0207 (6)
H5	1.012 (4)	0.287 (3)	0.375 (3)	0.026 (9)*
C6	1.0046 (3)	0.3283 (3)	0.5132 (2)	0.0180 (6)
H6	0.915 (5)	0.298 (4)	0.522 (3)	0.041 (11)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.01005 (16)	0.01992 (18)	0.01464 (17)	−0.00140 (12)	0.00178 (12)	−0.00056 (13)
Cu2	0.01163 (16)	0.01659 (18)	0.01619 (19)	−0.00197 (12)	0.00101 (12)	0.00033 (13)
Cl1	0.0113 (3)	0.0285 (4)	0.0150 (3)	−0.0023 (2)	0.0024 (2)	−0.0022 (3)
Cl2	0.0143 (3)	0.0192 (3)	0.0168 (3)	−0.0023 (2)	0.0023 (2)	−0.0010 (3)
Cl3	0.0121 (3)	0.0232 (3)	0.0150 (3)	−0.0030 (2)	0.0021 (2)	−0.0004 (3)
Cl5	0.0131 (3)	0.0202 (3)	0.0176 (3)	−0.0023 (2)	0.0018 (2)	0.0012 (3)
Cl4	0.0176 (3)	0.0207 (3)	0.0246 (4)	−0.0038 (3)	−0.0003 (3)	−0.0039 (3)
N1	0.0148 (11)	0.0189 (12)	0.0153 (11)	0.0006 (9)	0.0018 (9)	0.0023 (9)
C11	0.0207 (15)	0.0381 (18)	0.0186 (15)	0.0010 (13)	0.0055 (12)	0.0054 (13)
C2	0.0134 (12)	0.0164 (13)	0.0189 (14)	0.0023 (10)	0.0001 (10)	−0.0001 (11)
C21	0.0203 (14)	0.0297 (16)	0.0219 (15)	−0.0035 (12)	−0.0005 (11)	−0.0073 (13)
C3	0.0174 (14)	0.0172 (13)	0.0209 (14)	−0.0016 (11)	0.0014 (11)	0.0024 (11)
C4	0.0225 (14)	0.0156 (13)	0.0192 (14)	0.0020 (11)	0.0028 (11)	0.0005 (11)
C41	0.0365 (18)	0.0292 (17)	0.0190 (15)	0.0001 (15)	0.0057 (13)	−0.0020 (13)
C5	0.0218 (14)	0.0195 (14)	0.0202 (15)	−0.0002 (12)	−0.0046 (12)	−0.0012 (12)
C6	0.0148 (13)	0.0178 (13)	0.0210 (15)	−0.0008 (11)	−0.0020 (11)	0.0018 (11)

Geometric parameters (Å, º)

Cu1—Cl1	2.2813 (7)	C2—C3	1.381 (4)
Cu1—Cl1^i	2.2938 (7)	C2—C21	1.492 (4)
Cu1—Cl2	2.2840 (7)	C21—H21A	0.9600
Cu1—Cl3	2.2959 (7)	C21—H21B	0.9600
Cu1—Cl5^ii	2.6055 (8)	C21—H21C	0.9600
Cu2—Cl2	2.3084 (7)	C3—C4	1.387 (4)
Cu2—Cl3	2.3289 (7)	C3—H3	0.89 (4)
Cu2—Cl3^ii	2.9485 (8)	C4—C5	1.400 (4)
Cu2—Cl4	2.2089 (8)	C4—C41	1.499 (4)
Cu2—Cl5	2.2620 (7)	C41—H41A	0.9600
N1—C6	1.351 (4)	C41—H41B	0.9600
N1—C2	1.356 (4)	C41—H41C	0.9600
N1—C11	1.479 (4)	C5—C6	1.373 (4)
C11—H11A	0.9600	C5—H5	0.91 (4)
C11—H11B	0.9600	C6—H6	0.89 (4)
C11—H11C	0.9600
Cl1—Cu1—Cl1^i	86.48 (3)	H11A—C11—H11B	109.5
Cl1—Cu1—Cl2	92.77 (3)	N1—C11—H11C	109.5
Cl1^i—Cu1—Cl2	163.89 (3)	H11A—C11—H11C	109.5
Cl1—Cu1—Cl3	167.89 (3)	H11B—C11—H11C	109.5
Cl1^i—Cu1—Cl3	91.41 (3)	N1—C2—C3	118.1 (3)
Cl1—Cu1—Cl5^ii	98.53 (3)	N1—C2—C21	119.4 (3)
Cl1^i—Cu1—Cl5^ii	101.26 (3)	C3—C2—C21	122.5 (3)
Cl2—Cu1—Cl3	85.95 (3)	C2—C21—H21A	109.5
Cl2—Cu1—Cl5^ii	94.78 (3)	C2—C21—H21B	109.5
Cl3—Cu1—Cl5^ii	93.58 (2)	H21A—C21—H21B	109.5
Cl2—Cu2—Cl3	84.64 (2)	C2—C21—H21C	109.5
Cl2—Cu2—Cl3^ii	89.76 (2)	H21A—C21—H21C	109.5
Cl2—Cu2—Cl4	91.21 (3)	H21B—C21—H21C	109.5
Cl2—Cu2—Cl5	173.69 (3)	C2—C3—C4	122.8 (3)
Cl3—Cu2—Cl3^ii	86.91 (2)	C2—C3—H3	118 (2)
Cl3—Cu2—Cl4	164.80 (3)	C4—C3—H3	119 (2)
Cl3^ii—Cu2—Cl4	107.73 (3)	C3—C4—C5	116.8 (3)
Cl3—Cu2—Cl5	90.76 (3)	C3—C4—C41	121.0 (3)
Cl3^ii—Cu2—Cl5	85.68 (2)	C5—C4—C41	122.2 (3)
Cl4—Cu2—Cl5	94.32 (3)	C4—C41—H41A	109.5
Cu1—Cl1—Cu1^i	93.52 (3)	C4—C41—H41B	109.5
Cu1—Cl2—Cu2	94.99 (3)	H41A—C41—H41B	109.5
Cu1—Cl3—Cu2	94.11 (3)	C4—C41—H41C	109.5
Cu1—Cl3—Cu2^ii	85.63 (3)	H41A—C41—H41C	109.5
Cu2—Cl3—Cu2^ii	93.09 (3)	H41B—C41—H41C	109.5
Cu1^ii—Cl5—Cu2	94.99 (3)	C4—C5—C6	119.7 (3)
C6—N1—C2	121.3 (2)	C4—C5—H5	122 (2)
C6—N1—C11	118.4 (2)	C6—C5—H5	118 (2)
C2—N1—C11	120.3 (2)	C5—C6—N1	121.3 (3)
N1—C11—H11A	109.5	C5—C6—H6	121 (3)
N1—C11—H11B	109.5	N1—C6—H6	118 (3)

Symmetry codes: (i) −x, −y, −z+1; (ii) −x+1, −y, −z+1.

(II) bis(1,2,4-trimethylpyridinium) hexa-µ-bromido-tetrabromidotetracuprate(II)

Crystal data

(C8H12N)2[Cu4Br10]	F(000) = 1200
Mr = 1297.68	Dx = 2.736 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 3793 reflections
a = 9.4742 (2) Å	θ = 1.0–27.5°
b = 11.7845 (4) Å	µ = 15.36 mm^−1
c = 14.1290 (4) Å	T = 295 K
β = 93.408 (2)°	Needle, dark purple
V = 1574.69 (8) Å^3	0.26 × 0.09 × 0.04 mm
Z = 2

Data collection

Nonius KappaCCD area-detector diffractometer	3607 independent reflections
Radiation source: fine-focus sealed tube	2490 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.040
Detector resolution: 9 pixels mm^-1	θmax = 27.5°, θmin = 3.9°
CCD rotation images, thick slices scans	h = −12→12
Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997)	k = −15→15
Tmin = 0.159, Tmax = 0.566	l = −18→18
7001 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.039	H-atom parameters constrained
wR(F^2) = 0.094	w = 1/[σ^2(Fo^2) + (0.0466P)^2 + 0.1744P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max = 0.002
3607 reflections	Δρmax = 0.62 e Å^−3
149 parameters	Δρmin = −0.55 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0032 (2)

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cu1	0.18140 (5)	0.03054 (6)	0.51529 (4)	0.03885 (18)
Cu2	0.51531 (6)	0.17205 (6)	0.52161 (5)	0.03871 (18)
Br1	−0.01933 (5)	0.03438 (6)	0.61277 (4)	0.05058 (19)
Br2	0.31969 (5)	0.14949 (5)	0.62535 (4)	0.04173 (16)
Br3	0.36383 (5)	0.06383 (5)	0.40532 (4)	0.04229 (17)
Br4	0.61492 (6)	0.31321 (6)	0.62180 (5)	0.0604 (2)
Br5	0.70317 (5)	0.17464 (5)	0.41582 (4)	0.04612 (17)
N1	1.0788 (4)	0.3801 (4)	0.5822 (3)	0.0435 (11)
C11	1.0130 (6)	0.3744 (7)	0.6735 (5)	0.069 (2)
H11A	1.0062	0.4494	0.6993	0.104*
H11B	1.0696	0.3278	0.7166	0.104*
H11C	0.9201	0.3422	0.6643	0.104*
C2	1.2074 (5)	0.4315 (5)	0.5759 (4)	0.0394 (12)
C21	1.2782 (6)	0.4861 (6)	0.6611 (4)	0.0630 (18)
H21A	1.2163	0.5419	0.6857	0.094*
H21B	1.3640	0.5219	0.6440	0.094*
H21C	1.2999	0.4295	0.7087	0.094*
C3	1.2693 (6)	0.4289 (5)	0.4902 (4)	0.0446 (13)
H3	1.3561	0.4645	0.4852	0.054*
C4	1.2074 (7)	0.3756 (5)	0.4114 (4)	0.0497 (14)
C41	1.2798 (9)	0.3739 (7)	0.3194 (5)	0.080 (2)
H41A	1.3730	0.3428	0.3299	0.120*
H41B	1.2863	0.4499	0.2955	0.120*
H41C	1.2262	0.3280	0.2741	0.120*
C5	1.0749 (6)	0.3241 (5)	0.4209 (4)	0.0569 (16)
H5	1.0287	0.2879	0.3694	0.068*
C6	1.0150 (6)	0.3275 (5)	0.5060 (5)	0.0551 (16)
H6	0.9278	0.2927	0.5119	0.066*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0268 (3)	0.0544 (4)	0.0357 (4)	−0.0050 (3)	0.0044 (3)	−0.0028 (3)
Cu2	0.0316 (3)	0.0426 (4)	0.0418 (4)	−0.0064 (3)	0.0012 (3)	0.0016 (3)
Br1	0.0293 (3)	0.0885 (5)	0.0344 (3)	−0.0084 (3)	0.0059 (2)	−0.0100 (3)
Br2	0.0388 (3)	0.0477 (3)	0.0391 (3)	−0.0066 (2)	0.0057 (2)	−0.0035 (3)
Br3	0.0308 (3)	0.0612 (4)	0.0352 (3)	−0.0091 (2)	0.0051 (2)	−0.0012 (3)
Br4	0.0544 (3)	0.0552 (4)	0.0711 (5)	−0.0150 (3)	−0.0003 (3)	−0.0153 (3)
Br5	0.0356 (3)	0.0548 (4)	0.0483 (3)	−0.0112 (2)	0.0055 (2)	0.0028 (3)
N1	0.039 (2)	0.053 (3)	0.039 (3)	0.002 (2)	0.001 (2)	0.006 (2)
C11	0.045 (3)	0.106 (6)	0.058 (4)	0.007 (3)	0.020 (3)	0.017 (4)
C2	0.040 (3)	0.039 (3)	0.039 (3)	0.000 (2)	−0.001 (2)	0.001 (2)
C21	0.063 (4)	0.072 (5)	0.053 (4)	−0.008 (3)	−0.004 (3)	−0.019 (4)
C3	0.048 (3)	0.043 (3)	0.044 (3)	−0.005 (3)	0.007 (2)	0.003 (3)
C4	0.073 (4)	0.041 (3)	0.035 (3)	0.003 (3)	0.007 (3)	0.002 (3)
C41	0.116 (6)	0.078 (6)	0.048 (4)	−0.004 (5)	0.017 (4)	−0.001 (4)
C5	0.074 (4)	0.048 (4)	0.047 (4)	−0.008 (3)	−0.013 (3)	−0.001 (3)
C6	0.045 (3)	0.059 (4)	0.060 (4)	−0.012 (3)	−0.011 (3)	0.010 (3)

Geometric parameters (Å, º)

Cu1—Br1	2.4139 (7)	C2—C3	1.377 (7)
Cu1—Br1^i	2.4262 (8)	C2—C21	1.489 (8)
Cu1—Br2	2.4202 (8)	C21—H21A	0.9600
Cu1—Br3	2.4238 (7)	C21—H21B	0.9600
Cu1—Br5^ii	2.8042 (9)	C21—H21C	0.9600
Cu2—Br2	2.4449 (7)	C3—C4	1.379 (8)
Cu2—Br3	2.4709 (8)	C3—H3	0.9300
Cu2—Br3^ii	3.1565 (9)	C4—C5	1.408 (8)
Cu2—Br4	2.3458 (9)	C4—C41	1.505 (8)
Cu2—Br5	2.3915 (7)	C41—H41A	0.9600
N1—C6	1.355 (7)	C41—H41B	0.9600
N1—C2	1.368 (6)	C41—H41C	0.9600
N1—C11	1.467 (7)	C5—C6	1.359 (8)
C11—H11A	0.9600	C5—H5	0.9300
C11—H11B	0.9600	C6—H6	0.9300
C11—H11C	0.9600
Br1—Cu1—Br1^i	86.92 (3)	H11A—C11—H11B	109.5
Br1—Cu1—Br2	92.14 (3)	N1—C11—H11C	109.5
Br1^i—Cu1—Br2	162.99 (4)	H11A—C11—H11C	109.5
Br1—Cu1—Br3	168.16 (4)	H11B—C11—H11C	109.5
Br1^i—Cu1—Br3	90.96 (3)	N1—C2—C3	118.3 (5)
Br2—Cu1—Br3	86.49 (2)	N1—C2—C21	119.9 (5)
Br1—Cu1—Br5^ii	97.03 (3)	C3—C2—C21	121.8 (5)
Br1^i—Cu1—Br5^ii	101.74 (3)	C2—C21—H21A	109.5
Br2—Cu1—Br5^ii	95.24 (3)	C2—C21—H21B	109.5
Br3—Cu1—Br5^ii	94.81 (3)	H21A—C21—H21B	109.5
Br2—Cu2—Br3	84.92 (2)	C2—C21—H21C	109.5
Br2—Cu2—Br3^ii	88.93 (2)	H21A—C21—H21C	109.5
Br2—Cu2—Br4	90.43 (3)	H21B—C21—H21C	109.5
Br2—Cu2—Br5	174.27 (4)	C2—C3—C4	122.5 (5)
Br3—Cu2—Br3^ii	87.02 (2)	C2—C3—H3	118.7
Br3—Cu2—Br4	164.62 (4)	C4—C3—H3	118.7
Br3^ii—Cu2—Br4	107.58 (3)	C3—C4—C5	117.2 (5)
Br3—Cu2—Br5	90.88 (3)	C3—C4—C41	120.6 (6)
Br3^ii—Cu2—Br5	86.94 (2)	C5—C4—C41	122.1 (6)
Br4—Cu2—Br5	94.61 (3)	C4—C41—H41A	109.5
Cu1—Br1—Cu1^i	93.08 (3)	C4—C41—H41B	109.5
Cu1—Br2—Cu2	94.50 (3)	H41A—C41—H41B	109.5
Cu1—Br3—Cu2	93.75 (3)	C4—C41—H41C	109.5
Cu1—Br3—Cu2^ii	84.63 (4)	H41A—C41—H41C	109.5
Cu2—Br3—Cu2^ii	92.98 (4)	H41B—C41—H41C	109.5
Cu1^ii—Br5—Cu2	93.52 (3)	C4—C5—C6	119.6 (6)
C6—N1—C2	120.5 (5)	C4—C5—H5	120.2
C6—N1—C11	119.0 (5)	C6—C5—H5	120.2
C2—N1—C11	120.3 (5)	C5—C6—N1	121.7 (5)
N1—C11—H11A	109.5	C5—C6—H6	119.1
N1—C11—H11B	109.5	N1—C6—H6	119.1

Symmetry codes: (i) −x, −y, −z+1; (ii) −x+1, −y, −z+1.

(III) bis(3,4-dimethylpyridinium) hexa-µ-bromido-tetrabromidotetracuprate(II)

Crystal data

(C7H10N)2[Cu4Br10]	F(000) = 1168
Mr = 1269.55	Dx = 2.879 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 3462 reflections
a = 9.5112 (4) Å	θ = 2.9–27.5°
b = 12.3581 (5) Å	µ = 16.52 mm^−1
c = 12.4617 (6) Å	T = 295 K
β = 91.502 (3)°	Block, dark purple
V = 1464.25 (11) Å^3	0.25 × 0.18 × 0.09 mm
Z = 2

Data collection

Nonius KappaCCD area-detector diffractometer	3368 independent reflections
Graphite monochromator	2555 reflections with I > 2σ(I)
Detector resolution: 9 pixels mm^-1	Rint = 0.032
CCD scans	θmax = 27.7°, θmin = 4.9°
Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997)	h = −12→12
Tmin = 0.105, Tmax = 0.222	k = −16→16
6393 measured reflections	l = −16→16

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.046	H-atom parameters constrained
wR(F^2) = 0.150	w = 1/[σ^2(Fo^2) + (0.0951P)^2 + 1.4586P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max = 0.001
3368 reflections	Δρmax = 1.17 e Å^−3
139 parameters	Δρmin = −1.46 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0015 (4)

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cu1	0.17891 (8)	0.03245 (8)	0.51613 (7)	0.0351 (2)
Cu2	0.51470 (8)	0.15955 (7)	0.52720 (7)	0.0340 (2)
Br1	−0.02549 (7)	0.03433 (8)	0.62710 (6)	0.0471 (2)
Br2	0.30803 (7)	0.14884 (6)	0.63833 (6)	0.0395 (2)
Br3	0.36865 (7)	0.06147 (6)	0.39225 (6)	0.0396 (2)
Br4	0.61884 (9)	0.28319 (7)	0.64902 (7)	0.0490 (3)
Br5	0.70687 (7)	0.16282 (6)	0.40592 (6)	0.0395 (2)
N1	0.9683 (7)	0.3107 (6)	0.5188 (7)	0.0571 (19)
H1	0.8959	0.2710	0.5048	0.069*
C2	1.0647 (9)	0.3219 (7)	0.4444 (7)	0.0478 (18)
H2	1.0513	0.2877	0.3784	0.057*
C3	1.1839 (9)	0.3831 (6)	0.4626 (7)	0.0446 (17)
C31	1.2913 (12)	0.3930 (8)	0.3797 (8)	0.067 (3)
H31A	1.2663	0.3475	0.3198	0.101*
H31B	1.3811	0.3711	0.4093	0.101*
H31C	1.2965	0.4669	0.3563	0.101*
C4	1.1963 (7)	0.4359 (5)	0.5622 (6)	0.0365 (15)
C41	1.3221 (9)	0.5027 (7)	0.5902 (7)	0.052 (2)
H41A	1.3988	0.4562	0.6115	0.078*
H41B	1.3009	0.5504	0.6483	0.078*
H41C	1.3481	0.5444	0.5289	0.078*
C5	1.0923 (9)	0.4228 (7)	0.6352 (6)	0.0474 (18)
H5	1.0992	0.4588	0.7006	0.057*
C6	0.9798 (9)	0.3584 (8)	0.6139 (8)	0.057 (2)
H6	0.9117	0.3479	0.6651	0.069*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0248 (4)	0.0492 (5)	0.0315 (5)	−0.0043 (3)	0.0033 (3)	−0.0029 (3)
Cu2	0.0313 (4)	0.0371 (5)	0.0335 (5)	−0.0058 (3)	0.0018 (3)	0.0004 (3)
Br1	0.0276 (3)	0.0837 (6)	0.0301 (4)	−0.0079 (3)	0.0046 (3)	−0.0090 (4)
Br2	0.0351 (4)	0.0461 (4)	0.0377 (4)	−0.0058 (3)	0.0058 (3)	−0.0069 (3)
Br3	0.0304 (3)	0.0583 (5)	0.0302 (4)	−0.0104 (3)	0.0037 (3)	−0.0005 (3)
Br4	0.0518 (5)	0.0527 (5)	0.0426 (5)	−0.0170 (3)	0.0013 (3)	−0.0084 (3)
Br5	0.0358 (4)	0.0453 (4)	0.0375 (4)	−0.0111 (3)	0.0044 (3)	−0.0022 (3)
N1	0.049 (4)	0.048 (4)	0.075 (6)	−0.017 (3)	−0.007 (4)	0.006 (4)
C2	0.059 (5)	0.048 (4)	0.037 (4)	−0.005 (4)	−0.001 (4)	−0.013 (3)
C3	0.052 (4)	0.042 (4)	0.040 (4)	−0.006 (3)	0.005 (3)	−0.002 (3)
C31	0.089 (7)	0.070 (6)	0.044 (5)	−0.024 (5)	0.028 (5)	−0.013 (4)
C4	0.037 (3)	0.034 (3)	0.038 (4)	−0.001 (3)	−0.002 (3)	0.005 (3)
C41	0.045 (4)	0.056 (5)	0.055 (5)	−0.015 (4)	−0.006 (4)	−0.012 (4)
C5	0.052 (4)	0.055 (5)	0.035 (4)	−0.003 (4)	0.002 (3)	0.002 (3)
C6	0.050 (5)	0.063 (5)	0.060 (6)	−0.009 (4)	0.008 (4)	0.002 (5)

Geometric parameters (Å, º)

Cu1—Br1	2.4152 (10)	C2—H2	0.9300
Cu1—Br1^i	2.4207 (11)	C3—C4	1.405 (11)
Cu1—Br2	2.4079 (11)	C3—C31	1.477 (11)
Cu1—Br3	2.4321 (9)	C31—H31A	0.9600
Cu1—Br5^ii	2.8092 (12)	C31—H31B	0.9600
Cu2—Br2	2.4376 (10)	C31—H31C	0.9600
Cu2—Br3	2.4707 (11)	C4—C5	1.370 (10)
Cu2—Br3^ii	3.1049 (12)	C4—C41	1.487 (10)
Cu2—Br4	2.3540 (11)	C41—H41A	0.9600
Cu2—Br5	2.4024 (10)	C41—H41B	0.9600
N1—C6	1.326 (12)	C41—H41C	0.9600
N1—C2	1.328 (11)	C5—C6	1.355 (12)
N1—H1	0.8600	C5—H5	0.9300
C2—C3	1.377 (11)	C6—H6	0.9300
Br1—Cu1—Br1^i	86.95 (3)	C2—N1—H1	118.8
Br1—Cu1—Br2	92.12 (4)	N1—C2—C3	121.5 (8)
Br1^i—Cu1—Br2	163.25 (5)	N1—C2—H2	119.3
Br1—Cu1—Br3	169.69 (5)	C3—C2—H2	119.3
Br1^i—Cu1—Br3	91.45 (4)	C2—C3—C4	116.8 (7)
Br2—Cu1—Br3	86.48 (3)	C2—C3—C31	120.8 (8)
Br1—Cu1—Br5^ii	96.90 (4)	C4—C3—C31	122.4 (7)
Br1^i—Cu1—Br5^ii	100.50 (4)	C3—C31—H31A	109.5
Br2—Cu1—Br5^ii	96.21 (4)	C3—C31—H31B	109.5
Br3—Cu1—Br5^ii	93.41 (3)	H31A—C31—H31B	109.5
Br2—Cu2—Br3	84.99 (3)	C3—C31—H31C	109.5
Br2—Cu2—Br3^ii	93.16 (3)	H31A—C31—H31C	109.5
Br2—Cu2—Br4	90.05 (4)	H31B—C31—H31C	109.5
Br2—Cu2—Br5	175.19 (4)	C3—C4—C5	119.0 (7)
Br3—Cu2—Br3^ii	88.75 (3)	C3—C4—C41	120.9 (7)
Br3—Cu2—Br4	167.67 (5)	C5—C4—C41	120.1 (7)
Br3—Cu2—Br5	90.20 (3)	C4—C41—H41A	109.5
Br3^ii—Cu2—Br4	102.81 (4)	C4—C41—H41B	109.5
Br3^ii—Cu2—Br5	86.95 (3)	H41A—C41—H41B	109.5
Br4—Cu2—Br5	94.62 (4)	C4—C41—H41C	109.5
Cu1—Br1—Cu1^i	93.05 (3)	H41A—C41—H41C	109.5
Cu1—Br2—Cu2	94.51 (4)	H41B—C41—H41C	109.5
Cu1—Br3—Cu2	93.07 (3)	C4—C5—C6	121.4 (8)
Cu1—Br3—Cu2^ii	85.98 (30	C4—C5—H5	119.3
Cu2—Br3—Cu2^ii	91.25 (3)	C6—C5—H5	119.3
Cu2—Br5—Cu1^ii	93.54 (3)	C5—C6—N1	118.9 (8)
C2—N1—C6	122.4 (7)	C5—C6—H6	120.6
C6—N1—H1	118.8	N1—C6—H6	120.6

Symmetry codes: (i) −x, −y, −z+1; (ii) −x+1, −y, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Br5	0.86	2.53	3.364 (7)	163

(IV) bis(2,3-dimethylpyridinium) hexa-µ-chlorido-tetrachloridotetracuprate(II)

Crystal data

(C7H10N)2[Cu4Br10]	F(000) = 1168
Mr = 1269.55	Dx = 2.831 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 9.7548 (5) Å	Cell parameters from 3960 reflections
b = 12.5783 (8) Å	θ = 2.9–29.1°
c = 12.2179 (5) Å	µ = 16.24 mm^−1
β = 96.459 (3)°	T = 295 K
V = 1489.61 (14) Å^3	Irregular, dark purple
Z = 2	0.19 × 0.16 × 0.10 mm

Data collection

Nonius KappaCCD area-detector diffractometer	3901 independent reflections
Graphite monochromator	2141 reflections with I > 2σ(I)
Detector resolution: 9 pixels mm^-1	Rint = 0.074
CCD scans	θmax = 29.1°, θmin = 4.1°
Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997)	h = −13→13
Tmin = 0.093, Tmax = 0.197	k = −17→16
7293 measured reflections	l = −16→16

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.050	H-atom parameters constrained
wR(F^2) = 0.113	w = 1/[σ^2(Fo^2) + (0.0423P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.03	(Δ/σ)max < 0.001
3901 reflections	Δρmax = 0.79 e Å^−3
139 parameters	Δρmin = −0.93 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0084 (3)

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cu1	0.17977 (8)	0.02941 (9)	0.51430 (7)	0.0361 (3)
Cu2	0.51035 (8)	0.15398 (8)	0.51864 (7)	0.0337 (2)
Br1	−0.00935 (7)	0.03861 (9)	0.62755 (6)	0.0485 (3)
Br2	0.32045 (7)	0.15254 (7)	0.63208 (6)	0.0422 (2)
Br3	0.35053 (7)	0.05366 (8)	0.38347 (6)	0.0406 (2)
Br4	0.62951 (8)	0.28248 (8)	0.63832 (6)	0.0468 (3)
Br5	0.68157 (8)	0.15251 (7)	0.39361 (6)	0.0420 (2)
N1	1.1156 (7)	0.3209 (6)	0.3878 (5)	0.0492 (19)
H1	1.1296	0.2979	0.3237	0.059*
C2	1.2126 (7)	0.3836 (7)	0.4419 (6)	0.0393 (19)
C21	1.3383 (8)	0.4033 (9)	0.3857 (7)	0.058 (3)
H21A	1.3373	0.3574	0.3228	0.086*
H21B	1.4191	0.3892	0.4359	0.086*
H21C	1.3392	0.4761	0.3620	0.086*
C3	1.1922 (7)	0.4224 (7)	0.5449 (6)	0.042 (2)
C31	1.2969 (9)	0.4914 (9)	0.6074 (7)	0.069 (3)
H31A	1.2619	0.5166	0.6730	0.103*
H31B	1.3168	0.5508	0.5625	0.103*
H31C	1.3798	0.4513	0.6271	0.103*
C4	1.0730 (9)	0.3934 (9)	0.5881 (7)	0.056 (3)
H4	1.0564	0.4177	0.6573	0.067*
C5	0.9756 (9)	0.3263 (9)	0.5265 (8)	0.066 (3)
H5	0.8952	0.3063	0.5554	0.079*
C6	1.0001 (9)	0.2923 (8)	0.4272 (8)	0.061 (3)
H6	0.9366	0.2489	0.3860	0.074*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0217 (4)	0.0521 (7)	0.0351 (5)	−0.0053 (4)	0.0056 (3)	−0.0027 (4)
Cu2	0.0263 (4)	0.0383 (6)	0.0368 (5)	−0.0058 (4)	0.0054 (3)	−0.0004 (4)
Br1	0.0240 (4)	0.0877 (8)	0.0345 (4)	−0.0101 (4)	0.0065 (3)	−0.0122 (4)
Br2	0.0315 (4)	0.0514 (6)	0.0451 (4)	−0.0082 (4)	0.0105 (3)	−0.0110 (4)
Br3	0.0276 (4)	0.0603 (6)	0.0342 (4)	−0.0103 (4)	0.0049 (3)	−0.0010 (4)
Br4	0.0477 (5)	0.0481 (6)	0.0448 (4)	−0.0170 (4)	0.0063 (3)	−0.0066 (4)
Br5	0.0327 (4)	0.0515 (6)	0.0432 (4)	−0.0109 (4)	0.0106 (3)	−0.0013 (4)
N1	0.047 (4)	0.054 (5)	0.046 (4)	−0.017 (4)	−0.001 (3)	−0.005 (3)
C2	0.032 (4)	0.044 (5)	0.042 (4)	−0.004 (4)	0.004 (3)	0.005 (4)
C21	0.045 (5)	0.071 (8)	0.060 (5)	−0.014 (5)	0.019 (4)	0.004 (5)
C3	0.033 (4)	0.051 (6)	0.040 (4)	0.003 (4)	−0.005 (3)	0.000 (4)
C31	0.063 (7)	0.077 (9)	0.062 (6)	−0.006 (6)	−0.010 (5)	−0.019 (6)
C4	0.048 (5)	0.072 (8)	0.048 (5)	0.020 (5)	0.013 (4)	0.015 (5)
C5	0.037 (5)	0.074 (8)	0.089 (7)	−0.009 (5)	0.015 (5)	0.027 (6)
C6	0.049 (5)	0.061 (7)	0.073 (6)	−0.031 (5)	0.001 (4)	0.000 (5)

Geometric parameters (Å, º)

Cu1—Br1	2.4302 (11)	C2—C21	1.492 (10)
Cu1—Br1^i	2.4189 (11)	C21—H21A	0.9600
Cu1—Br2	2.4307 (12)	C21—H21B	0.9600
Cu1—Br3	2.4539 (11)	C21—H21C	0.9600
Cu1—Br5^ii	2.8266 (14)	C3—C4	1.378 (11)
Cu2—Br2	2.4352 (11)	C3—C31	1.485 (11)
Cu2—Br3	2.4842 (11)	C31—H31A	0.9600
Cu2—Br3^ii	3.1190 (13)	C31—H31B	0.9600
Cu2—Br4	2.3915 (12)	C31—H31C	0.9600
Cu2—Br5	2.3870 (11)	C4—C5	1.421 (13)
N1—C6	1.325 (10)	C4—H4	0.9300
N1—C2	1.347 (10)	C5—C6	1.333 (12)
N1—H1	0.8600	C5—H5	0.9300
C2—C3	1.385 (10)	C6—H6	0.9300
Br1^i—Cu1—Br1	85.42 (4)	C2—N1—H1	118.0
Br1—Cu1—Br2	92.68 (4)	N1—C2—C3	119.2 (7)
Br1^i—Cu1—Br2	161.13 (6)	N1—C2—C21	116.1 (7)
Br1—Cu1—Br3	168.34 (6)	C3—C2—C21	124.7 (7)
Br1^i—Cu1—Br3	92.26 (4)	C2—C21—H21A	109.5
Br2—Cu1—Br3	85.82 (4)	C2—C21—H21B	109.5
Br1—Cu1—Br5^ii	99.89 (4)	H21A—C21—H21B	109.5
Br1^i—Cu1—Br5^ii	104.97 (5)	C2—C21—H21C	109.5
Br2—Cu1—Br5^ii	93.85 (4)	H21A—C21—H21C	109.5
Br3—Cu1—Br5^ii	91.74 (4)	H21B—C21—H21C	109.5
Br2—Cu2—Br3	85.06 (4)	C2—C3—C4	117.9 (8)
Br2—Cu2—Br4	90.32 (4)	C2—C3—C31	120.8 (8)
Br2—Cu2—Br5	174.87 (5)	C4—C3—C31	121.3 (8)
Br2—Cu2—Br3^ii	95.83 (4)	C3—C31—H31A	109.5
Br3—Cu2—Br3^ii	92.47 (4)	C3—C31—H31B	109.5
Br3—Cu2—Br4	167.24 (5)	H31A—C31—H31B	109.5
Br3—Cu2—Br5	90.15 (4)	C3—C31—H31C	109.5
Br4—Cu2—Br5	93.99 (4)	H31A—C31—H31C	109.5
Br3^ii—Cu2—Br4	99.84 (4)	H31B—C31—H31C	109.5
Br3^ii—Cu2—Br5	86.18 (4)	C3—C4—C5	119.8 (8)
Cu1—Br1—Cu1^i	94.58 (4)	C3—C4—H4	120.1
Cu1—Br2—Cu2	94.74 (4)	C5—C4—H4	120.1
Cu1—Br3—Cu2	92.94 (4)	C4—C5—C6	119.7 (8)
Cu1—Br3—Cu2^ii	86.80 (4)	C4—C5—H5	120.2
Cu2—Br3—Cu2^ii	87.53 (4)	C6—C5—H5	120.2
Cu2—Br5—Cu1^ii	95.13 (4)	C5—C6—N1	119.4 (8)
C6—N1—C2	124.1 (7)	C5—C6—H6	120.3
C6—N1—H1	118.0	N1—C6—H6	120.3

Symmetry codes: (i) −x, −y, −z+1; (ii) −x+1, −y, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Br4^iii	0.86	2.48	3.330 (7)	170

Symmetry code: (iii) x+1/2, −y+1/2, z−1/2.

(V) bis(1-methylpyridinium) hexa-µ₂-bromido-tetrabromidotetracuprate(II)

Crystal data

(C6H8N)2[Cu4Br10]	F(000) = 1136
Mr = 1241.52	Dx = 3.015 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 7605 reflections
a = 12.0358 (3) Å	θ = 1.0–40.3°
b = 9.5125 (2) Å	µ = 17.68 mm^−1
c = 12.4133 (3) Å	T = 295 K
β = 105.756 (1)°	Needle, dark purple
V = 1367.81 (6) Å^3	0.18 × 0.07 × 0.03 mm
Z = 2

Data collection

Nonius KappaCCD area-detector diffractometer	4736 independent reflections
Radiation source: fine-focus sealed tube	2706 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.062
Detector resolution: 9 pixels mm^-1	θmax = 32.0°, θmin = 4.0°
CCD rotation images, thick slices scans	h = −17→17
Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997)	k = −14→14
Tmin = 0.226, Tmax = 0.618	l = −18→18
9228 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.043	H-atom parameters constrained
wR(F^2) = 0.091	w = 1/[σ^2(Fo^2) + (0.0345P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.02	(Δ/σ)max = 0.001
4736 reflections	Δρmax = 0.89 e Å^−3
129 parameters	Δρmin = −0.91 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0166 (4)

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cu1	0.47381 (5)	0.18080 (5)	1.01565 (5)	0.03446 (16)
Cu2	0.33248 (5)	0.51056 (6)	1.01251 (5)	0.03162 (15)
Br1	0.50466 (6)	−0.02507 (5)	1.13368 (5)	0.04569 (16)
Br2	0.37910 (4)	0.30798 (5)	1.13681 (4)	0.03472 (13)
Br3	0.41234 (5)	0.37128 (5)	0.88367 (4)	0.03760 (14)
Br4	0.20814 (5)	0.60113 (6)	1.11409 (5)	0.04973 (17)
Br5	0.30907 (4)	0.70798 (5)	0.89072 (5)	0.03792 (14)
N1	0.0863 (3)	0.1897 (4)	1.0651 (4)	0.0381 (10)
C11	0.0417 (5)	0.2633 (7)	1.1515 (5)	0.0623 (18)
H11A	0.0877	0.3454	1.1773	0.093*
H11B	0.0460	0.2011	1.2134	0.093*
H11C	−0.0371	0.2907	1.1192	0.093*
C2	0.0810 (4)	0.2543 (6)	0.9687 (5)	0.0448 (13)
H2	0.0483	0.3434	0.9552	0.054*
C3	0.1232 (5)	0.1908 (7)	0.8898 (5)	0.0516 (15)
H3	0.1188	0.2360	0.8224	0.062*
C4	0.1726 (5)	0.0587 (7)	0.9102 (6)	0.0596 (17)
H4	0.2022	0.0143	0.8573	0.072*
C5	0.1769 (5)	−0.0052 (6)	1.0103 (5)	0.0508 (15)
H5	0.2097	−0.0940	1.0257	0.061*
C6	0.1340 (5)	0.0604 (6)	1.0864 (5)	0.0482 (14)
H6	0.1371	0.0164	1.1541	0.058*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0493 (4)	0.0227 (3)	0.0355 (4)	0.0054 (2)	0.0185 (3)	0.0039 (2)
Cu2	0.0375 (3)	0.0276 (3)	0.0323 (3)	0.0063 (2)	0.0138 (3)	0.0020 (2)
Br1	0.0816 (4)	0.0245 (3)	0.0378 (3)	0.0084 (2)	0.0279 (3)	0.0060 (2)
Br2	0.0413 (3)	0.0319 (2)	0.0348 (3)	0.0045 (2)	0.0170 (2)	0.0047 (2)
Br3	0.0587 (3)	0.0267 (3)	0.0298 (3)	0.0091 (2)	0.0161 (2)	0.00302 (19)
Br4	0.0551 (4)	0.0530 (3)	0.0499 (4)	0.0188 (3)	0.0292 (3)	0.0060 (3)
Br5	0.0435 (3)	0.0314 (3)	0.0421 (3)	0.0098 (2)	0.0172 (2)	0.0075 (2)
N1	0.035 (2)	0.043 (2)	0.038 (3)	−0.0036 (19)	0.013 (2)	−0.008 (2)
C11	0.069 (4)	0.067 (4)	0.062 (4)	0.004 (3)	0.038 (4)	−0.014 (3)
C2	0.042 (3)	0.053 (3)	0.040 (3)	0.004 (3)	0.011 (3)	0.008 (3)
C3	0.048 (3)	0.076 (4)	0.031 (3)	−0.008 (3)	0.012 (3)	−0.001 (3)
C4	0.048 (4)	0.075 (4)	0.062 (4)	0.000 (3)	0.023 (3)	−0.028 (4)
C5	0.041 (3)	0.041 (3)	0.065 (4)	0.002 (2)	0.005 (3)	−0.015 (3)
C6	0.045 (3)	0.054 (4)	0.042 (3)	−0.004 (3)	0.008 (3)	0.001 (3)

Geometric parameters (Å, º)

Cu1—Br1	2.4133 (7)	C11—H11A	0.9600
Cu1—Br1^i	2.4410 (8)	C11—H11B	0.9600
Cu1—Br2	2.4405 (7)	C11—H11C	0.9600
Cu1—Br3	2.4200 (7)	C2—C3	1.361 (7)
Cu1—Br5^ii	2.7658 (8)	C2—H2	0.9300
Cu2—Br2	2.4370 (7)	C3—C4	1.384 (9)
Cu2—Br3	2.4641 (7)	C3—H3	0.9300
Cu2—Br3^ii	3.1949 (8)	C4—C5	1.371 (8)
Cu2—Br4	2.3657 (8)	C4—H4	0.9300
Cu2—Br5	2.3792 (7)	C5—C6	1.347 (8)
N1—C2	1.331 (6)	C5—H5	0.9300
N1—C6	1.353 (7)	C6—H6	0.9300
N1—C11	1.497 (6)
Br1—Cu1—Br1^i	86.45 (2)	Cu2—Br5—Cu1^ii	95.71 (2)
Br1—Cu1—Br2	92.79 (3)	C2—N1—C11	119.2 (5)
Br1^i—Cu1—Br2	158.82 (4)	C6—N1—C11	120.1 (5)
Br1—Cu1—Br3	170.73 (3)	N1—C11—H11A	109.5
Br1^i—Cu1—Br3	90.93 (3)	N1—C11—H11B	109.5
Br2—Cu1—Br3	86.44 (2)	H11A—C11—H11B	109.5
Br1—Cu1—Br5^ii	94.77 (3)	N1—C11—H11C	109.5
Br1^i—Cu1—Br5^ii	105.56 (3)	H11A—C11—H11C	109.5
Br2—Cu1—Br5^ii	95.60 (3)	H11B—C11—H11C	109.5
Br3—Cu1—Br5^ii	94.49 (2)	C2—N1—C6	120.7 (5)
Br2—Cu2—Br3	85.55 (2)	N1—C2—C3	120.4 (5)
Br2—Cu2—Br3^ii	89.54 (2)	N1—C2—H2	119.8
Br2—Cu2—Br4	91.19 (3)	C3—C2—H2	119.8
Br2—Cu2—Br5	173.55 (3)	C2—C3—C4	119.8 (6)
Br3—Cu2—Br3^ii	87.09 (2)	C2—C3—H3	120.1
Br3—Cu2—Br4	163.03 (3)	C4—C3—H3	120.1
Br3^ii—Cu2—Br4	109.56 (3)	C3—C4—C5	118.5 (5)
Br3—Cu2—Br5	90.67 (2)	C3—C4—H4	120.8
Br3^ii—Cu2—Br5	85.05 (2)	C5—C4—H4	120.8
Br4—Cu2—Br5	93.92 (3)	C4—C5—C6	120.2 (5)
Cu1—Br1—Cu1^i	93.55 (2)	C4—C5—H5	119.9
Cu1—Br2—Cu2	93.88 (2)	C6—C5—H5	119.9
Cu1—Br3—Cu2	93.71 (3)	C5—C6—N1	120.4 (5)
Cu1—Br3—Cu2^ii	84.64 (3)	C5—C6—H6	119.8
Cu2—Br3—Cu2^ii	92.91 (3)	N1—C6—H6	119.8

Symmetry codes: (i) −x+1, −y, −z+2; (ii) −x+1, −y+1, −z+2.

(VI) bis(trimethylphenylammonium) hexa-µ₂-bromido-tetrabromidocuprate(II)

Crystal data

(C9H14N)2[Cu4Br10]	Z = 1
Mr = 1325.66	F(000) = 616
Triclinic, P1	Dx = 2.613 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.3969 (1) Å	Cell parameters from 20082 reflections
b = 11.8734 (2) Å	θ = 2.9–35.0°
c = 12.2699 (3) Å	µ = 14.36 mm^−1
α = 107.693 (1)°	T = 295 K
β = 100.607 (1)°	Needle, dark purple
γ = 100.888 (1)°	0.21 × 0.17 × 0.14 mm
V = 842.33 (3) Å^3

Data collection

Nonius KappaCCD area-detector diffractometer	5868 independent reflections
Radiation source: fine-focus sealed tube	3831 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.072
Detector resolution: 9 pixels mm^-1	θmax = 32.2°, θmin = 3.9°
CCD rotation images, thick slices scans	h = −9→9
Absorption correction: analytical (Alcock, 1974)	k = −17→17
Tmin = 0.104, Tmax = 0.257	l = −18→18
25097 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.045	H-atom parameters constrained
wR(F^2) = 0.113	w = 1/[σ^2(Fo^2) + (0.0472P)^2 + 0.571P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max < 0.001
5868 reflections	Δρmax = 1.03 e Å^−3
158 parameters	Δρmin = −1.26 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0054 (4)

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cu1	0.84987 (8)	0.10508 (5)	0.05623 (4)	0.03649 (13)
Cu2	0.46196 (7)	0.25731 (4)	0.16479 (4)	0.03296 (12)
Br1	0.86484 (6)	−0.02218 (4)	−0.13910 (3)	0.03442 (10)
Br2	0.53800 (7)	0.16495 (4)	−0.02738 (3)	0.04314 (12)
Br3	0.78259 (7)	0.19680 (4)	0.24579 (3)	0.03930 (11)
Br4	0.16774 (7)	0.32035 (4)	0.06760 (4)	0.04076 (12)
Br5	0.46227 (8)	0.37818 (5)	0.35656 (4)	0.04954 (14)
N1	0.9824 (6)	0.6306 (4)	0.2881 (4)	0.0504 (9)
C11	0.8084 (9)	0.5407 (5)	0.1820 (5)	0.0612 (13)
H11A	0.6830	0.5089	0.2066	0.092*
H11B	0.8660	0.4747	0.1435	0.092*
H11C	0.7649	0.5810	0.1280	0.092*
C12	1.0451 (11)	0.5619 (6)	0.3683 (6)	0.0826 (19)
H12A	1.1681	0.6139	0.4332	0.124*
H12B	1.0850	0.4907	0.3247	0.124*
H12C	0.9224	0.5371	0.3982	0.124*
C13	1.1826 (9)	0.6756 (6)	0.2505 (7)	0.089 (2)
H13A	1.1434	0.7131	0.1932	0.134*
H13B	1.2399	0.6079	0.2159	0.134*
H13C	1.2927	0.7347	0.3182	0.134*
C1	0.8927 (7)	0.7347 (4)	0.3461 (4)	0.0401 (9)
C2	0.8510 (9)	0.8111 (4)	0.2849 (4)	0.0529 (11)
H2	0.8808	0.7982	0.2114	0.064*
C3	0.7641 (9)	0.9079 (5)	0.3336 (5)	0.0606 (13)
H3	0.7344	0.9597	0.2926	0.073*
C4	0.7228 (8)	0.9264 (5)	0.4423 (5)	0.0637 (14)
H4	0.6687	0.9924	0.4764	0.076*
C5	0.7611 (10)	0.8479 (6)	0.5009 (5)	0.0682 (15)
H5	0.7310	0.8605	0.5744	0.082*
C6	0.8440 (9)	0.7500 (5)	0.4522 (4)	0.0574 (12)
H6	0.8660	0.6956	0.4913	0.069*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0363 (3)	0.0486 (3)	0.0289 (2)	0.0236 (2)	0.01094 (19)	0.0107 (2)
Cu2	0.0331 (2)	0.0386 (3)	0.0298 (2)	0.0159 (2)	0.01102 (18)	0.0099 (2)
Br1	0.0362 (2)	0.0425 (2)	0.02863 (19)	0.01923 (17)	0.01085 (15)	0.01122 (17)
Br2	0.0410 (2)	0.0647 (3)	0.0300 (2)	0.0311 (2)	0.01129 (16)	0.01371 (19)
Br3	0.0415 (2)	0.0519 (2)	0.0288 (2)	0.02513 (19)	0.01045 (16)	0.01168 (18)
Br4	0.0426 (2)	0.0474 (2)	0.0409 (2)	0.02410 (19)	0.01394 (17)	0.01822 (19)
Br5	0.0527 (3)	0.0632 (3)	0.0329 (2)	0.0276 (2)	0.01585 (19)	0.0067 (2)
N1	0.046 (2)	0.048 (2)	0.062 (2)	0.0175 (18)	0.0170 (18)	0.021 (2)
C11	0.064 (3)	0.046 (3)	0.060 (3)	0.008 (2)	0.015 (3)	0.004 (2)
C12	0.086 (4)	0.074 (4)	0.092 (5)	0.040 (3)	−0.003 (3)	0.038 (4)
C13	0.052 (3)	0.077 (4)	0.133 (6)	0.014 (3)	0.048 (4)	0.018 (4)
C1	0.043 (2)	0.041 (2)	0.038 (2)	0.0108 (18)	0.0083 (17)	0.0157 (18)
C2	0.074 (3)	0.050 (3)	0.040 (2)	0.021 (2)	0.018 (2)	0.020 (2)
C3	0.076 (3)	0.048 (3)	0.059 (3)	0.022 (3)	0.004 (3)	0.024 (2)
C4	0.053 (3)	0.052 (3)	0.070 (4)	0.016 (2)	0.013 (3)	0.000 (3)
C5	0.078 (4)	0.077 (4)	0.047 (3)	0.016 (3)	0.029 (3)	0.015 (3)
C6	0.073 (3)	0.061 (3)	0.045 (3)	0.016 (3)	0.015 (2)	0.028 (2)

Geometric parameters (Å, º)

Cu1—Br1	2.4441 (6)	C12—H12C	0.9600
Cu1—Br1^i	2.4366 (5)	N1—C13	1.500 (7)
Cu1—Br2	2.4007 (5)	C13—H13A	0.9600
Cu1—Br2^ii	3.5416 (7)	C13—H13B	0.9600
Cu1—Br3	2.4057 (6)	C13—H13C	0.9600
Cu1—Br4^iii	2.8987 (7)	N1—C1	1.499 (5)
Cu2—Br1^ii	3.0465 (6)	C1—C6	1.361 (6)
Cu2—Br2	2.4599 (6)	C1—C2	1.375 (6)
Cu2—Br3	2.4395 (5)	C2—H2	0.9300
Cu2—Br4	2.4027 (5)	C2—C3	1.390 (7)
Cu2—Br5	2.3539 (6)	C3—H3	0.9300
N1—C11	1.498 (6)	C3—C4	1.367 (7)
C11—H11A	0.9600	C4—H4	0.9300
C11—H11B	0.9600	C4—C5	1.370 (8)
C11—H11C	0.9600	C5—H5	0.9300
N1—C12	1.504 (6)	C5—C6	1.385 (8)
C12—H12A	0.9600	C6—H6	0.9300
C12—H12B	0.9600
Br1—Cu1—Br1^i	87.103 (18)	C12—N1—C13	107.9 (5)
Br1—Cu1—Br2	91.994 (19)	N1—C11—H11A	109.5
Br1^i—Cu1—Br2	173.18 (3)	N1—C11—H11B	109.5
Br1—Cu1—Br2^ii	81.905 (18)	H11A—C11—H11B	109.5
Br1^i—Cu1—Br2^ii	87.475 (18)	N1—C11—H11C	109.5
Br1—Cu1—Br3	169.07 (3)	H11A—C11—H11C	109.5
Br1^i—Cu1—Br3	92.830 (19)	H11B—C11—H11C	109.5
Br1—Cu1—Br4^iii	95.24 (2)	N1—C12—H12A	109.5
Br1^i—Cu1—Br4^iii	92.774 (19)	N1—C12—H12B	109.5
Br2—Cu1—Br2^ii	85.703 (19)	H12A—C12—H12B	109.5
Br2—Cu1—Br3	86.776 (18)	N1—C12—H12C	109.5
Br2^ii—Cu1—Br3	87.172 (19)	H12A—C12—H12C	109.5
Br2—Cu1—Br4^iii	94.04 (2)	H12B—C12—H12C	109.5
Br2^ii—Cu1—Br4^iii	177.122 (19)	N1—C13—H13A	109.5
Br3—Cu1—Br4^iii	95.68 (2)	N1—C13—H13B	109.5
Br1^ii—Cu2—Br2	92.86 (2)	H13A—C13—H13B	109.5
Br1^ii—Cu2—Br3	94.023 (19)	N1—C13—H13C	109.5
Br1^ii—Cu2—Br4	89.879 (19)	H13A—C13—H13C	109.5
Br1^ii—Cu2—Br5	99.19 (2)	H13B—C13—H13C	109.5
Br2—Cu2—Br3	84.737 (18)	N1—C1—C2	117.2 (4)
Br2—Cu2—Br4	89.557 (19)	N1—C1—C6	121.7 (4)
Br2—Cu2—Br5	167.34 (3)	C2—C1—C6	121.0 (4)
Br3—Cu2—Br4	173.23 (2)	C1—C2—C3	119.7 (4)
Br3—Cu2—Br5	90.52 (2)	C1—C2—H2	120.2
Br4—Cu2—Br5	94.31 (2)	C3—C2—H2	120.2
Cu1^i—Br1—Cu1	92.897 (18)	C2—C3—C4	119.5 (5)
Cu1—Br1—Cu2^ii	98.748 (19)	C2—C3—H3	120.2
Cu1^i—Br1—Cu2^ii	86.512 (19)	C4—C3—H3	120.2
Cu1—Br2—Cu2	94.041 (19)	C3—C4—C5	120.1 (5)
Cu1—Br2—Cu1^ii	94.298 (19)	C3—C4—H4	120.0
Cu1^ii—Br2—Cu2	86.470 (19)	C5—C4—H4	120.0
Cu1—Br3—Cu2	94.439 (19)	C4—C5—C6	120.8 (5)
Cu1^iv—Br4—Cu2	90.574 (19)	C4—C5—H5	119.6
C1—N1—C11	109.1 (3)	C6—C5—H5	119.6
C11—N1—C12	106.9 (4)	C5—C6—C1	118.9 (5)
C11—N1—C13	109.5 (4)	C5—C6—H6	120.6
C1—N1—C12	112.5 (4)	C1—C6—H6	120.6
C1—N1—C13	110.9 (4)

Symmetry codes: (i) −x+2, −y, −z; (ii) −x+1, −y, −z; (iii) x+1, y, z; (iv) x−1, y, z.

(VII) bis(2,4-dimethylpyridinium) hexa-µ-bromido-tetrabromidotetracuprate(II)

Crystal data

(C7H10N)2[Cu4Br10]	F(000) = 1168
Mr = 1269.55	Dx = 2.967 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 4.0370 (1) Å	Cell parameters from 2968 reflections
b = 22.3375 (6) Å	θ = 2.9–26.4°
c = 15.8508 (3) Å	µ = 17.02 mm^−1
β = 96.095 (2)°	T = 295 K
V = 1421.29 (6) Å^3	Block, dark purple
Z = 2	0.24 × 0.18 × 0.08 mm

Data collection

Nonius KappaCCD area-detector diffractometer	2881 independent reflections
Graphite monochromator	2224 reflections with I > 2σ(I)
Detector resolution: 9 pixels mm^-1	Rint = 0.029
CCD scans	θmax = 26.4°, θmin = 3.2°
Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997)	h = −5→5
Tmin = 0.111, Tmax = 0.258	k = −27→27
5670 measured reflections	l = −19→19

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.045	H-atom parameters constrained
wR(F^2) = 0.138	w = 1/[σ^2(Fo^2) + (0.0867P)^2 + 1.6496P] where P = (Fo^2 + 2Fc^2)/3
S = 1.07	(Δ/σ)max < 0.001
2881 reflections	Δρmax = 1.62 e Å^−3
137 parameters	Δρmin = −1.42 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0015 (4)

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cu1	0.77714 (18)	0.47194 (3)	0.40724 (4)	0.0284 (3)
Cu2	0.3311 (2)	0.41386 (4)	0.21700 (5)	0.0313 (3)
Br1	1.18732 (15)	0.43363 (3)	0.51702 (4)	0.0283 (2)
Br2	0.73421 (16)	0.37808 (3)	0.33424 (4)	0.0286 (2)
Br3	0.35161 (16)	0.50869 (3)	0.30201 (4)	0.0272 (2)
Br4	0.28398 (17)	0.31607 (3)	0.15901 (4)	0.0353 (2)
Br5	−0.08927 (19)	0.45516 (3)	0.11824 (4)	0.0420 (3)
N1	1.1080 (17)	0.1602 (3)	0.4739 (4)	0.0445 (16)
H1	1.1849	0.1579	0.5266	0.053*
C2	1.1407 (17)	0.2124 (3)	0.4331 (4)	0.0337 (15)
C21	1.292 (2)	0.2632 (4)	0.4810 (5)	0.049 (2)
H21A	1.298	0.2972	0.4441	0.059*
H21B	1.5154	0.253	0.5035	0.059*
H21C	1.1636	0.2727	0.5267	0.059*
C3	1.0244 (18)	0.2139 (3)	0.3481 (4)	0.0356 (16)
H3	1.0455	0.249	0.3174	0.043*
C4	0.8764 (18)	0.1642 (3)	0.3074 (4)	0.0342 (16)
C41	0.749 (2)	0.1682 (4)	0.2142 (4)	0.048 (2)
H41A	0.5921	0.2004	0.2056	0.058*
H41B	0.6423	0.1313	0.1963	0.058*
H41C	0.9326	0.1754	0.1816	0.058*
C5	0.842 (2)	0.1135 (4)	0.3537 (5)	0.0445 (19)
H5	0.7351	0.0802	0.3283	0.053*
C6	0.964 (2)	0.1120 (4)	0.4374 (5)	0.048 (2)
H6	0.9455	0.0772	0.4687	0.057*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0347 (5)	0.0249 (5)	0.0238 (4)	0.0033 (4)	−0.0058 (3)	−0.0054 (3)
Cu2	0.0376 (5)	0.0266 (5)	0.0277 (4)	0.0026 (4)	−0.0065 (3)	−0.0061 (3)
Br1	0.0358 (4)	0.0239 (4)	0.0237 (3)	0.0032 (3)	−0.0037 (3)	−0.0037 (3)
Br2	0.0351 (4)	0.0232 (4)	0.0264 (4)	0.0026 (3)	−0.0022 (3)	−0.0041 (3)
Br3	0.0316 (4)	0.0246 (4)	0.0242 (3)	0.0007 (3)	−0.0027 (3)	−0.0022 (3)
Br4	0.0423 (4)	0.0285 (4)	0.0354 (4)	−0.0036 (3)	0.0053 (3)	−0.0103 (3)
Br5	0.0504 (5)	0.0384 (5)	0.0333 (4)	0.0074 (3)	−0.0136 (3)	−0.0048 (3)
N1	0.069 (4)	0.035 (4)	0.028 (3)	−0.001 (3)	0.002 (3)	0.006 (3)
C2	0.034 (4)	0.037 (4)	0.030 (3)	0.008 (3)	0.003 (3)	0.002 (3)
C21	0.064 (6)	0.037 (5)	0.045 (4)	0.000 (4)	−0.003 (4)	0.006 (4)
C3	0.052 (4)	0.023 (4)	0.032 (3)	0.006 (3)	0.007 (3)	0.004 (3)
C4	0.042 (4)	0.036 (4)	0.025 (3)	0.010 (3)	0.007 (3)	0.003 (3)
C41	0.067 (5)	0.049 (5)	0.026 (4)	0.004 (4)	−0.003 (3)	0.001 (3)
C5	0.056 (5)	0.034 (4)	0.044 (4)	−0.002 (4)	0.006 (4)	−0.003 (4)
C6	0.071 (6)	0.035 (5)	0.038 (4)	0.006 (4)	0.009 (4)	0.016 (4)

Geometric parameters (Å, º)

Cu1—Br1	2.4271 (9)	C2—C21	1.462 (11)
Cu1—Br1^i	2.4237 (9)	C21—H21A	0.96
Cu1—Br1^ii	3.2109 (10)	C21—H21B	0.96
Cu1—Br2	2.3922 (9)	C21—H21C	0.96
Cu1—Br3	2.4080 (9)	C2—C3	1.380 (9)
Cu1—Br3^iii	3.1074 (10)	C3—H3	0.93
Cu2—Br2	2.4696 (10)	C3—C4	1.388 (10)
Cu2—Br2^ii	3.2937 (11)	C4—C41	1.513 (9)
Cu2—Br3	2.5071 (10)	C41—H41A	0.96
Cu2—Br4	2.3698 (10)	C41—H41B	0.96
Cu2—Br5	2.3700 (10)	C41—H41C	0.96
Cu2—Br5^iii	3.0913 (12)	C4—C5	1.364 (10)
N1—C6	1.327 (10)	C5—H5	0.93
N1—C2	1.348 (9)	C5—C6	1.366 (10)
N1—H1	0.86	C6—H6	0.93
Br1—Cu1—Br1^i	87.24 (3)	Cu2—Br2—Cu2^iii	87.71 (3)
Br1^i—Cu1—Br1^ii	88.39 (3)	Cu1—Br3—Cu2	93.71 (3)
Br1—Cu1—Br1^ii	90.36 (3)	Cu1—Br3—Cu1^ii	93.23 (3)
Br1—Cu1—Br2	92.67 (3)	Cu1^ii—Br3—Cu2	94.67 (3)
Br1^i—Cu1—Br2	178.88 (4)	Cu2—Br5—Cu2^ii	94.40 (3)
Br1^ii—Cu1—Br2	90.50 (3)	C6—N1—C2	123.6 (6)
Br1—Cu1—Br3	177.53 (4)	C6—N1—H1	118.2
Br1^i—Cu1—Br3	92.68 (3)	C2—N1—H1	118.2
Br1—Cu1—Br3^iii	89.24 (3)	N1—C2—C21	118.6 (6)
Br1^i—Cu1—Br3^iii	91.59 (3)	C3—C2—C21	124.7 (7)
Br1^ii—Cu1—Br3	87.17 (3)	C2—C21—H21A	109.5
Br1^ii—Cu1—Br3^iii	179.60 (3)	C2—C21—H21B	109.5
Br2—Cu1—Br3	87.36 (3)	H21A—C21—H21B	109.5
Br2—Cu1—Br3^iii	89.53 (3)	C2—C21—H21C	109.5
Br3—Cu1—Br3^iii	93.23 (3)	H21A—C21—H21C	109.5
Br2—Cu2—Br2^ii	87.71 (3)	H21B—C21—H21C	109.5
Br2—Cu2—Br3	83.54 (3)	N1—C2—C3	116.7 (7)
Br2^ii—Cu2—Br3	83.47 (3)	C2—C3—C4	121.3 (7)
Br2—Cu2—Br4	90.73 (3)	C2—C3—H3	119.3
Br2^ii—Cu2—Br4	87.81 (3)	C4—C3—H3	119.3
Br2—Cu2—Br5	172.50 (4)	C3—C4—C5	118.5 (6)
Br2^ii—Cu2—Br5	87.24 (3)	C3—C4—C41	119.4 (6)
Br2^ii—Cu2—Br5^iii	175.28 (3)	C5—C4—C41	122.0 (7)
Br2—Cu2—Br5^iii	90.22 (3)	C4—C41—H41A	109.5
Br3—Cu2—Br4	169.74 (4)	C4—C41—H41B	109.5
Br3—Cu2—Br5	90.38 (3)	H41A—C41—H41B	109.5
Br3—Cu2—Br5^iii	92.09 (3)	C4—C41—H41C	109.5
Br4—Cu2—Br5	94.60 (3)	H41A—C41—H41C	109.5
Br4—Cu2—Br5^iii	96.46 (3)	H41B—C41—H41C	109.5
Br5—Cu2—Br5^iii	94.40 (3)	C4—C5—C6	119.7 (7)
Cu1—Br1—Cu1^i	92.76 (3)	C4—C5—H5	120.1
Cu1—Br1—Cu1^iii	90.36 (3)	C6—C5—H5	120.1
Cu1^i—Br1—Cu1^iii	91.62 (3)	C5—C6—N1	120.1 (7)
Cu1—Br2—Cu2	95.07 (3)	C5—C6—H6	120
Cu1—Br2—Cu2^iii	92.32 (3)	N1—C6—H6	120

Symmetry codes: (i) −x+2, −y+1, −z+1; (ii) x−1, y, z; (iii) x+1, y, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Br4^iv	0.86	2.84	3.378 (6)	122
N1—H1···Br5^v	0.86	3.01	3.573 (6)	125

Symmetry codes: (iv) x+1/2, −y+1/2, z+1/2; (v) x+3/2, −y+1/2, z+1/2.

(VIII) bis(3-chloro-1-methylpyridinium) octa-µ₂-chlorido-tetrachloridopentacuprate(II)

Crystal data

(C6ClH7N)[Cu5Br12]	F(000) = 1398
Mr = 1533.74	Dx = 3.091 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 7334 reflections
a = 6.3630 (1) Å	θ = 1.0–35.0°
b = 22.9814 (2) Å	µ = 17.90 mm^−1
c = 11.2713 (1) Å	T = 295 K
β = 91.205 (1)°	Needle, dark red
V = 1647.84 (3) Å^3	0.31 × 0.10 × 0.05 mm
Z = 2

Data collection

Nonius KappaCCD area-detector diffractometer	7180 independent reflections
Radiation source: fine-focus sealed tube	5015 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.035
Detector resolution: 9 pixels mm^-1	θmax = 34.9°, θmin = 3.3°
CCD rotation images, thick slices scans	h = −10→10
Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997)	k = −37→37
Tmin = 0.029, Tmax = 0.269	l = −18→18
14150 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.038	H-atom parameters constrained
wR(F^2) = 0.095	w = 1/[σ^2(Fo^2) + (0.0373P)^2 + 1.7303P] where P = (Fo^2 + 2Fc^2)/3
S = 1.03	(Δ/σ)max = 0.002
7180 reflections	Δρmax = 1.01 e Å^−3
153 parameters	Δρmin = −1.02 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0046 (2)

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cu1	1.0000	0.0000	0.0000	0.03242 (12)
Cu2	0.57335 (6)	0.051900 (18)	0.16017 (4)	0.03311 (10)
Cu3	0.09654 (6)	0.105631 (18)	0.28134 (3)	0.03053 (9)
Br1	0.84998 (5)	0.093903 (14)	0.04195 (3)	0.03240 (8)
Br2	0.70642 (4)	−0.042910 (14)	0.09943 (3)	0.03077 (8)
Br3	0.40599 (5)	0.145495 (15)	0.18568 (3)	0.03815 (9)
Br4	0.26709 (5)	0.010089 (15)	0.24901 (3)	0.03521 (8)
Br5	−0.02166 (6)	0.200252 (16)	0.33125 (3)	0.03924 (9)
Br6	−0.18462 (5)	0.056258 (15)	0.37558 (3)	0.03464 (8)
Cl3	0.3718 (2)	0.32981 (7)	0.22780 (11)	0.0750 (4)
N1	0.8852 (5)	0.30017 (13)	0.0522 (2)	0.0375 (6)
C11	1.0011 (8)	0.24843 (19)	0.0107 (4)	0.0591 (12)
H11A	0.9094	0.2248	−0.0378	0.089*
H11B	1.0502	0.2263	0.0780	0.089*
H11C	1.1189	0.2607	−0.0348	0.089*
C2	0.7106 (6)	0.29284 (17)	0.1145 (3)	0.0412 (8)
H2	0.6656	0.2556	0.1341	0.049*
C3	0.5980 (6)	0.34089 (19)	0.1496 (3)	0.0430 (8)
C4	0.6643 (7)	0.39598 (19)	0.1198 (3)	0.0493 (9)
H4	0.5884	0.4286	0.1423	0.059*
C5	0.8442 (7)	0.40162 (17)	0.0564 (4)	0.0511 (10)
H5	0.8925	0.4384	0.0362	0.061*
C6	0.9536 (6)	0.35321 (17)	0.0223 (3)	0.0453 (9)
H6	1.0750	0.3572	−0.0214	0.054*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0278 (2)	0.0266 (3)	0.0434 (3)	−0.0001 (2)	0.0129 (2)	−0.0023 (2)
Cu2	0.02504 (17)	0.0270 (2)	0.0478 (2)	0.00050 (14)	0.01187 (15)	−0.00133 (17)
Cu3	0.02516 (17)	0.0287 (2)	0.0379 (2)	0.00095 (14)	0.00545 (14)	−0.00266 (16)
Br1	0.02924 (14)	0.02594 (16)	0.04243 (17)	0.00009 (11)	0.01050 (12)	−0.00019 (12)
Br2	0.02709 (14)	0.02720 (16)	0.03835 (16)	−0.00055 (11)	0.00817 (11)	−0.00147 (12)
Br3	0.02811 (15)	0.02710 (16)	0.0597 (2)	0.00080 (12)	0.01118 (14)	−0.00028 (14)
Br4	0.02641 (14)	0.02938 (17)	0.05029 (19)	0.00041 (11)	0.01193 (12)	0.00087 (14)
Br5	0.04127 (18)	0.03249 (18)	0.04416 (19)	0.00609 (14)	0.00537 (14)	−0.00534 (14)
Br6	0.02951 (14)	0.03426 (17)	0.04049 (17)	0.00030 (12)	0.00887 (12)	−0.00122 (13)
Cl3	0.0583 (7)	0.1068 (12)	0.0608 (7)	0.0074 (7)	0.0189 (5)	0.0101 (7)
N1	0.0462 (16)	0.0317 (15)	0.0344 (14)	−0.0031 (12)	−0.0003 (12)	0.0044 (11)
C11	0.072 (3)	0.041 (2)	0.065 (3)	0.008 (2)	0.018 (2)	0.001 (2)
C2	0.0471 (19)	0.0370 (19)	0.0394 (18)	−0.0075 (16)	−0.0007 (15)	0.0091 (15)
C3	0.0425 (18)	0.055 (2)	0.0319 (17)	0.0004 (17)	−0.0015 (14)	0.0008 (15)
C4	0.065 (3)	0.041 (2)	0.042 (2)	0.0081 (19)	−0.0055 (18)	−0.0035 (17)
C5	0.063 (3)	0.0287 (19)	0.061 (3)	−0.0129 (18)	−0.005 (2)	0.0067 (17)
C6	0.051 (2)	0.038 (2)	0.047 (2)	−0.0101 (16)	0.0013 (16)	0.0078 (16)

Geometric parameters (Å, º)

Cu1—Br1	2.4106 (3)	C11—H11A	0.9600
Cu1—Br2	2.4096 (3)	C11—H11B	0.9600
Cu1—Br4^i	3.2587 (4)	C11—H11C	0.9600
Cu2—Br1	2.4299 (5)	N1—C2	1.338 (5)
Cu2—Br2	2.4408 (5)	N1—C6	1.339 (5)
Cu2—Br2^i	3.3991 (5)	C2—C3	1.379 (6)
Cu2—Br3	2.4199 (5)	C2—H2	0.9300
Cu2—Br4	2.4095 (5)	C3—Cl3	1.722 (4)
Cu2—Br6^ii	2.8495 (6)	C3—C4	1.378 (6)
Cu3—Br1^iii	3.1042 (5)	C4—H4	0.9300
Cu3—Br3	2.4430 (5)	C4—C5	1.369 (6)
Cu3—Br4	2.4795 (5)	C5—H5	0.9300
Cu3—Br5	2.3724 (5)	C5—C6	1.371 (6)
Cu3—Br6	2.3867 (5)	C6—H6	0.9300
N1—C11	1.480 (5)
Br1—Cu1—Br2	87.770 (10)	Cu1—Br2—Cu2^i	91.238 (14)
Br1—Cu1—Br4^i	91.784 (10)	Cu2—Br2—Cu2^i	96.732 (14)
Br2—Cu1—Br4^i	88.629 (9)	Cu2—Br3—Cu3	94.582 (17)
Br1—Cu2—Br6^ii	93.929 (16)	Cu2—Br4—Cu3	93.913 (17)
Br1—Cu2—Br2	86.631 (15)	Cu1^i—Br4—Cu2	94.712 (17)
Br1—Cu2—Br2^i	85.665 (15)	Cu1^i—Br4—Cu3	88.146 (17)
Br1—Cu2—Br3	92.161 (17)	Cu2^iii—Br6—Cu3	91.962 (16)
Br1—Cu2—Br4	171.06 (2)	C2—N1—C6	121.6 (3)
Br2—Cu2—Br2^i	83.269 (15)	C2—N1—C11	119.3 (3)
Br2—Cu2—Br3	169.39 (2)	C6—N1—C11	119.0 (3)
Br2^i—Cu2—Br3	86.130 (16)	N1—C11—H11A	109.5
Br2—Cu2—Br4	92.806 (17)	N1—C11—H11B	109.5
Br2^i—Cu2—Br4	85.412 (15)	H11A—C11—H11B	109.5
Br2—Cu2—Br6^ii	94.928 (17)	N1—C11—H11C	109.5
Br2^i—Cu2—Br6^ii	178.170 (16)	H11A—C11—H11C	109.5
Br3—Cu2—Br4	86.751 (16)	H11B—C11—H11C	109.5
Br3—Cu2—Br6^ii	95.671 (18)	N1—C2—C3	119.5 (4)
Br4—Cu2—Br6^ii	95.005 (17)	N1—C2—H2	120.3
Br1^iii—Cu3—Br3	92.651 (16)	C3—C2—H2	120.3
Br1^iii—Cu3—Br4	90.582 (15)	C2—C3—C4	120.1 (4)
Br1^iii—Cu3—Br5	97.397 (17)	C2—C3—Cl3	118.3 (3)
Br1^iii—Cu3—Br6	88.609 (15)	C4—C3—Cl3	121.6 (3)
Br3—Cu3—Br4	84.716 (15)	C3—C4—C5	118.5 (4)
Br3—Cu3—Br5	91.341 (18)	C3—C4—H4	120.7
Br3—Cu3—Br6	173.40 (2)	C5—C4—H4	120.7
Br4—Cu3—Br5	171.27 (2)	C4—C5—C6	120.3 (4)
Br4—Cu3—Br6	88.791 (17)	C4—C5—H5	119.9
Br5—Cu3—Br6	94.927 (17)	C6—C5—H5	119.9
Cu1—Br1—Cu2	92.656 (14)	C5—C6—H6	120.0
Cu1—Br1—Cu3^ii	93.052 (14)	N1—C6—C5	119.9 (4)
Cu2—Br1—Cu3^ii	85.212 (14)	N1—C6—H6	120.0
Cu1—Br2—Cu2	92.409 (14)

Symmetry codes: (i) −x+1, −y, −z; (ii) x+1, y, z; (iii) x−1, y, z.

(IX) bis(2-chloro-1-methylpyridinium) dodeca-µ₂bromido-tetrabromidoheptacuprate(II)

Crystal data

(C6H7ClN)2[Cu7Br16]	Z = 1
Mr = 1980.49	F(000) = 897
Triclinic, P1	Dx = 3.465 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.2353 (1) Å	Cell parameters from 5354 reflections
b = 10.7361 (2) Å	θ = 2.9–30.0°
c = 12.8913 (2) Å	µ = 20.84 mm^−1
α = 90.985 (1)°	T = 295 K
β = 105.006 (1)°	Needle, dark purple
γ = 100.374 (1)°	0.28 × 0.12 × 0.08 mm
V = 949.27 (3) Å^3

Data collection

Nonius KappaCCD area-detector diffractometer	5540 independent reflections
Radiation source: fine-focus sealed tube	3851 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.030
Detector resolution: 9 pixels mm^-1	θmax = 30.0°, θmin = 3.0°
CCD rotation images, thick slices scans	h = −10→10
Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997)	k = −15→15
Tmin = 0.045, Tmax = 0.165	l = −17→18
9850 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.038	H-atom parameters constrained
wR(F^2) = 0.096	w = 1/[σ^2(Fo^2) + (0.0468P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.00	(Δ/σ)max = 0.001
5540 reflections	Δρmax = 1.24 e Å^−3
188 parameters	Δρmin = −1.01 e Å^−3
4 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0040 (2)

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
Cu1	0.5000	1.0000	0.5000	0.0371 (2)
Cu2	0.66624 (9)	0.96630 (5)	0.26954 (4)	0.02747 (13)
Cu3	0.73456 (8)	0.91556 (5)	0.01312 (4)	0.02845 (13)
Cu4	0.83166 (8)	0.85687 (5)	−0.24044 (4)	0.02804 (13)
Br1	0.61429 (7)	1.14129 (4)	0.37406 (3)	0.02909 (11)
Br2	0.54850 (7)	0.82832 (4)	0.39401 (3)	0.02839 (11)
Br3	0.71187 (6)	1.09738 (4)	0.12049 (3)	0.02577 (11)
Br4	0.63628 (7)	0.78398 (4)	0.14624 (3)	0.02932 (11)
Br5	0.81791 (6)	1.04245 (4)	−0.12692 (3)	0.02662 (11)
Br6	0.76130 (7)	0.73570 (4)	−0.09056 (3)	0.03057 (12)
Br7	0.93406 (6)	0.99782 (5)	−0.36506 (3)	0.03169 (12)
Br8	0.80711 (9)	0.66457 (5)	−0.33885 (4)	0.04306 (15)
N1	0.9815 (4)	0.5884 (3)	0.2396 (3)	0.0337 (9)	0.834 (4)
C11	1.1112 (12)	0.6159 (10)	0.1685 (7)	0.048 (2)	0.834 (4)
H11A	1.2220	0.6798	0.2037	0.072*	0.834 (4)
H11B	1.0419	0.6460	0.1028	0.072*	0.834 (4)
H11C	1.1543	0.5400	0.1527	0.072*	0.834 (4)
C2	0.8181 (6)	0.5042 (3)	0.21216 (19)	0.0349 (10)	0.834 (4)
Cl1	0.7451 (4)	0.4307 (2)	0.08112 (17)	0.0578 (7)	0.834 (4)
C3	0.6988 (7)	0.4758 (5)	0.2775 (4)	0.0433 (12)
H3	0.5858	0.4142	0.2560	0.052*
C4	0.7500 (9)	0.5412 (6)	0.3768 (4)	0.0519 (14)
H4	0.6703	0.5252	0.4231	0.062*
C5	0.9188 (9)	0.6296 (5)	0.4069 (4)	0.0501 (14)
H5	0.9549	0.6744	0.4737	0.060*
C6	1.0335 (8)	0.6514 (5)	0.3379 (4)	0.0431 (12)
H6	1.1495	0.7105	0.3586	0.052*
N1A	0.8181 (6)	0.5042 (3)	0.21216 (19)	0.0349 (10)	0.166 (4)
C11A	0.786 (5)	0.429 (3)	0.1106 (15)	0.018 (7)*	0.166 (4)
C2A	0.9815 (4)	0.5884 (3)	0.2396 (3)	0.0337 (9)	0.166 (4)
Cl1A	1.1548 (15)	0.6178 (14)	0.1647 (9)	0.039 (3)*	0.166 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0606 (6)	0.0280 (4)	0.0304 (4)	0.0026 (4)	0.0298 (4)	−0.0010 (3)
Cu2	0.0357 (3)	0.0286 (3)	0.0223 (3)	0.0060 (2)	0.0152 (2)	0.0015 (2)
Cu3	0.0386 (3)	0.0275 (3)	0.0234 (3)	0.0057 (2)	0.0161 (2)	0.0013 (2)
Cu4	0.0340 (3)	0.0300 (3)	0.0232 (3)	0.0059 (2)	0.0132 (2)	0.0014 (2)
Br1	0.0365 (3)	0.0287 (2)	0.0268 (2)	0.00599 (18)	0.01686 (18)	0.00167 (16)
Br2	0.0350 (3)	0.0290 (2)	0.0241 (2)	0.00409 (18)	0.01447 (18)	0.00051 (16)
Br3	0.0298 (2)	0.0273 (2)	0.0226 (2)	0.00627 (17)	0.01062 (17)	0.00189 (16)
Br4	0.0404 (3)	0.0273 (2)	0.0245 (2)	0.00683 (18)	0.01579 (19)	0.00256 (16)
Br5	0.0309 (2)	0.0280 (2)	0.0230 (2)	0.00546 (17)	0.01090 (17)	0.00261 (16)
Br6	0.0414 (3)	0.0271 (2)	0.0261 (2)	0.00434 (19)	0.01579 (19)	−0.00009 (16)
Br7	0.0267 (2)	0.0444 (3)	0.0238 (2)	0.00329 (19)	0.00848 (17)	0.00757 (18)
Br8	0.0663 (4)	0.0385 (3)	0.0319 (2)	0.0203 (3)	0.0194 (2)	−0.0014 (2)
N1	0.034 (2)	0.030 (2)	0.041 (2)	0.0101 (17)	0.0142 (18)	0.0060 (17)
C11	0.040 (5)	0.053 (5)	0.065 (5)	0.012 (4)	0.038 (4)	0.014 (3)
C2	0.038 (3)	0.030 (2)	0.039 (2)	0.0074 (19)	0.013 (2)	0.0040 (19)
Cl1	0.0748 (18)	0.0472 (11)	0.0429 (11)	−0.0011 (10)	0.0104 (12)	−0.0082 (9)
C3	0.033 (3)	0.039 (3)	0.057 (3)	0.003 (2)	0.013 (2)	0.007 (2)
C4	0.051 (4)	0.065 (4)	0.048 (3)	0.019 (3)	0.023 (3)	0.010 (3)
C5	0.048 (4)	0.063 (4)	0.041 (3)	0.014 (3)	0.014 (3)	−0.007 (3)
C6	0.034 (3)	0.043 (3)	0.047 (3)	0.004 (2)	0.007 (2)	−0.009 (2)
N1A	0.038 (3)	0.030 (2)	0.039 (2)	0.0074 (19)	0.013 (2)	0.0040 (19)
C2A	0.034 (2)	0.030 (2)	0.041 (2)	0.0101 (17)	0.0142 (18)	0.0060 (17)

Geometric parameters (Å, º)

Cu1—Br1	2.4390 (4)	Cu4—Br6	2.4581 (6)
Cu1—Br2	2.4046 (4)	Cu4—Br7	2.3908 (6)
Cu1—Br7^i	3.1762 (4)	Cu4—Br8	2.3589 (7)
Cu2—Br1	2.4323 (6)	N1—C11	1.4700 (1)
Cu2—Br2	2.4145 (6)	C11—H11A	0.9600
Cu2—Br3	2.4568 (6)	C11—H11B	0.9600
Cu2—Br4	2.4427 (6)	C11—H11C	0.9600
Cu2—Br5^i	3.4929 (7)	N1—C6	1.356 (6)
Cu2—Br7^ii	2.7869 (7)	N1—C2	1.314 (5)
Cu3—Br3	2.4277 (6)	C2—Cl1	1.760
Cu3—Br3^i	3.2200 (7)	C2—C3	1.356 (6)
Cu3—Br4	2.4083 (6)	C3—H3	0.9300
Cu3—Br5	2.4147 (6)	C3—C4	1.377 (7)
Cu3—Br5^ii	3.1355 (7)	C4—H4	0.9300
Cu3—Br6	2.3942 (6)	C4—C5	1.367 (8)
Cu4—Br1^i	3.2441 (7)	C5—H5	0.9300
Cu4—Br3^ii	3.2070 (7)	C5—C6	1.361 (7)
Cu4—Br5	2.4835 (6)	C6—H6	0.9300
Br1—Cu1—Br2	86.919 (13)	Br5—Cu4—Br8	171.60 (3)
Br1—Cu1—Br7^i	88.407 (13)	Br6—Cu4—Br7	171.11 (3)
Br2—Cu1—Br7^i	96.163 (14)	Br6—Cu4—Br8	89.45 (2)
Br1—Cu2—Br2	86.850 (19)	Br7—Cu4—Br8	97.63 (2)
Br1—Cu2—Br3	93.44 (2)	Cu1—Br1—Cu2	92.459 (18)
Br1—Cu2—Br4	166.59 (3)	Cu1—Br1—Cu4^i	90.69 (2)
Br1—Cu2—Br5^i	83.61 (2)	Cu2—Br1—Cu4^i	97.54 (2)
Br1—Cu2—Br7^ii	95.03 (2)	Cu1—Br2—Cu2	93.763 (18)
Br2—Cu2—Br3	167.62 (3)	Cu2—Br3—Cu3	92.02 (2)
Br2—Cu2—Br4	90.69 (2)	Cu2—Br3—Cu3^i	100.58 (2)
Br2—Cu2—Br5^i	88.44 (2)	Cu2—Br3—Cu4^ii	85.88 (2)
Br2—Cu2—Br7^ii	99.73 (2)	Cu3—Br3—Cu3^i	91.11 (2)
Br3—Cu2—Br4	86.168 (19)	Cu3—Br3—Cu4^ii	91.69 (2)
Br3—Cu2—Br5^i	79.299 (19)	Cu2—Br4—Cu3	92.84 (2)
Br3—Cu2—Br7^ii	92.58 (2)	Cu2^i—Br5—Cu3	94.34 (2)
Br4—Cu2—Br5^i	83.15 (2)	Cu2^i—Br5—Cu4	90.47 (2)
Br4—Cu2—Br7^ii	98.38 (2)	Cu3—Br5—Cu4	94.08 (2)
Br5^i—Cu2—Br7^ii	171.65 (2)	Cu3—Br6—Cu4	95.26 (2)
Br3—Cu3—Br3^i	88.89 (2)	Cu1^i—Br7—Cu4	93.24 (2)
Br3—Cu3—Br4	87.581 (19)	Cu2^ii—Br7—Cu4	97.36 (2)
Br3^i—Cu3—Br4	91.64 (2)	C2—N1—C6	118.6 (3)
Br3—Cu3—Br5	93.67 (2)	C2—N1—C11	122.7 (5)
Br3—Cu3—Br5^ii	89.28 (2)	C6—N1—C11	118.7 (5)
Br3^i—Cu3—Br5	85.760 (19)	N1—C11—H11A	109.5
Br3^i—Cu3—Br5^ii	172.82 (2)	N1—C11—H11B	109.5
Br3—Cu3—Br6	179.09 (3)	H11A—C11—H11B	109.5
Br3^i—Cu3—Br6	91.97 (2)	N1—C11—H11C	109.5
Br4—Cu3—Br5	177.09 (3)	H11A—C11—H11C	109.5
Br4—Cu3—Br5^ii	95.22 (2)	H11B—C11—H11C	109.5
Br4—Cu3—Br6	92.08 (2)	N1—C2—C3	123.5 (3)
Br5—Cu3—Br5^ii	87.43 (2)	N1—C2—Cl1	117.9 (3)
Br5—Cu3—Br6	86.71 (2)	C3—C2—Cl1	118.5 (3)
Br5^ii—Cu3—Br6	89.91 (2)	C2—C3—C4	118.0 (5)
Br1^i—Cu4—Br3^ii	170.38 (2)	C2—C3—H3	121.0
Br1^i—Cu4—Br5	88.334 (19)	C4—C3—H3	121.0
Br1^i—Cu4—Br6	98.05 (2)	C3—C4—C5	119.6 (5)
Br1^i—Cu4—Br7	87.657 (19)	C3—C4—H4	120.2
Br1^i—Cu4—Br8	87.61 (2)	C5—C4—H4	120.2
Br3^ii—Cu4—Br5	86.689 (19)	C4—C5—C6	119.2 (5)
Br3^ii—Cu4—Br6	89.59 (2)	C4—C5—H5	120.4
Br3^ii—Cu4—Br7	84.080 (19)	C6—C5—H5	120.4
Br3^ii—Cu4—Br8	98.34 (2)	C5—C6—N1	121.1 (5)
Br5—Cu4—Br6	83.839 (19)	C5—C6—H6	119.4
Br5—Cu4—Br7	89.55 (2)	N1—C6—H6	119.4

Symmetry codes: (i) −x+1, −y+2, −z; (ii) −x+2, −y+2, −z.