Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270113018386/sk3496sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270113018386/sk3496Isup2.hkl |
CCDC reference: 962903
8-Hydroxyquinoline (and derivatives thereof) is an aromatic Lewis base, acting as an efficient metal ion chelator. To this end, its metal cycle-forming abilities and the ensuing metal ionic complex stabilization (i) impart significant electronic properties to the resulting metal complex(es), which are useful in quantitative analytical determinations (Schneider & Roselli, 1970; Uri et al., 1957) and (ii) have rendered it useful in antimicrobial and fungicidal applications (Patel et al., 1999; Okide et al., 2000). The present crystal structure analysis of the title compound, (I), based on a twinned crystal, has revealed interesting methodological processing steps which are related to the basis of twinning theory, i.e. the existence in the lattice of a cell, simple or multiple, endowed either rigorously or approximately with more symmetry than the crystal (Donnay, 1940; Grimmer & Nespolo, 2006). In a recent publication (Guzei et al., 2012), which presents a detailed description of the steps needed to tackle structure solution and refinement problems from a data set obtained from pseudomerohedral twins, it was noted that the reason for this elaborate presentation was the lack of papers written in the form of tutorials with technical details on how to handle such cases. The motivation for writing the present paper is that, although there are pioneering works (Herbst-Irmer & Sheldrick, 1998; Cooper et al., 2002; Blake et al., 2009; Muller et al., 2007) that have boosted tremendously the field of structure solution and refinement from twinned crystals and works on the geometric theory of twinning (Donnay, 1940; Santoro, 1974; Grimmer & Nespolo, 2006), there is also a lack of works that combine both of these approaches in the study of twins. This combination provides an appropriate framework to peruse, understand and overcome problems during the structure analysis of a twinned crystal.
A reaction mixture containing zinc(II) nitrate (1.0 mmol), quinolin-8-ol (1 mmol) and 2-(2-hydroxynaphthalen-1-ylideneimino)-2-hydroxymethylpropane-1,3-diol (1 mmol) in methanol led immediately to a precipitate. Dissolution of the isolated precipitate in dimethyl sulfoxide (DMSO) afforded pale-yellow single crystals of (I) by slow evaporation at room temperature over a period of several weeks. The crystals were isolated by filtration and air-dried (yield 37%).
Crystal data, data collection and structure refinement details are summarized in Table 1. All H atoms were located in difference maps. C-bound H atoms were then treated as riding in geometrically idealized positions, with C—H = 0.95 Å and with Uiso(H) = 1.3Ueq(C). The hydroxy H atoms were refined freely.
Initially, index processing of images recorded from the studied crystal of (I), which present no indication for peak splitting, gave rise to a primitive unit cell with dimensions a = 11.099, b = 5.404 and c = 37.917 Å, and α = 90, β = 90.03 and γ = 90°, i.e. a seemingly orthorhombic cell. Using these cell dimensions in a search of the Cambridge Structural Database (CSD, Version 5.34; Allen, 2002), no structure was found containing any of the ligands used in the present study, indicating that the studied compound is a new one.
The structure was solved using direct methods in the monoclinic space group P21/a, a result which supports the slight deviation of β from 90°. In the asymmetric unit of the cell there are one and half molecules of the complex shown in the scheme. One ZnII cation is located on a general position, whereas the other one sits on a centre of symmetry. These two complexes are related by a noncrystallographic centre of symmetry, which renders the resulting structural model a pseudosymmetric one (Zwart et al., 2008). All data manipulations revealed almost all of the known warning signs of twinning (Herbst-Irmer & Sheldrick, 1998). The model was refined by considering the crystal as a pseudomerohedral twin (Castillo et al. 2010). The twin law is linked to a 180° rotation around the c crystallographic axis and in matrix form is (100/010/001). The main problem in the data analysis of this model was that the observed reflections were approximately half of the total unique reflections. A search of the CSD using the derived structural model revealed three previous structural studies (Merritt et al., 1954; Palenik, 1964; Chen et al., 2003). In Table 2, the unit-cell dimensions are given for all three published structural models. However, the pseudosymmetry characteristics of the present structural model raised suspicions as to the potential existence of a structure–superstructure relation between the models described in the monoclinic cell given in Table 2 and the pseudo-orthorhombic one emerging from our analysis.
Le Page (2002) has developed an algorithm and reformulated Mallard's law for the possible existence of a twin law in a lattice as a Diophantine system of two conditions: h.u = n and |h × u| < ntanδ, where n and δ meet Mallard's criterion limitations (n < 6 and ω < 6°; Grimmer & Nespolo, 2006), and h and u are reciprocal and direct lattice directions, respectively. Applying Le Page's algorithm as implemented in PLATON (Spek, 2009) for the monoclinic cell dimensions listed in Table 2, a supercell with dimensions a = 11.113, b = 5.411 and c = 37.967 Å, and α = 90, β = 90.06 and γ = 90° is obtained. The two cells are related through the transformation (a', b', c') = (a, b, a + 3c). This unit cell corresponds to the pseudo-orthorhombic unit cell initially used by us for solving the structure of (I).
Fig. 1(a) shows the structure–superstructure cell relationship. Primed axes concern the pseudo-orthorhombic cell and unprimed ones the monoclinic cell. This process also gives the h = (001) (possible mirror plane) and u = [103] (possible twofold axis) reciprocal and direct lattice vectors, respectively, for the lattices defined by the cells listed in Table 2, with n = 3 and δ < 0.13°. The perpendicularity condition (Donnay, 1940) for the monoclinic system and for vectors (hkl) = (001) and [uvw] = [103] affords [a/(ccosβ)] ~-3. Rearrangement of this equation yields [a/(3c)] = -cosβ, i.e. the relation joining a, c and β mentioned by Merritt et al. (1954). The calculated values of the [a/(ccosβ)] parameter for all data sets are given in the last column of Table 2.
Finally, using equation 5 given by Andrews & Johnson (1955) for (hkl) = (001) and [uvw] = [103], or in the equivalent tensorial form equation 2 of Calbick (1967), the two possible twin laws are derived. Either (001) is a twinning mirror plane and the twin law is (h2,k2,l2) = (h1,k1, (-2/3)h1-l1), or the [103] crystallographic direction is a 180° rotation twin axis and the twin law is (h2,k2,l2) = (-h1,-k1, (2/3)h1+l1). Equations 5 and 2 of the above-mentioned references refer to the case of a mirror twin plane. According to Calbick (1967), the same equations apply in the case of a 180° rotation twin axis by reversing the minus and plus signs in both of them.
This ambiguity concerning the twin law, which ultimately applies for the crystal of (I) studied here, is resolved experimentally. Reindexing of images was performed with the procedure implemented in the TwinSolve (Rigaku/MSC, 2002) environment of the CrystalClear program (Rigaku/MSC, 2005), and orientation matrices for components 1 and 2 were obtained. By applying the formula A2-1A1 (Bolte, 2004), the twin law (-1.000, 0.001, -0.001/0.000, -1.000, 0.000/0.668, 0.002, 1.000) of the 180° rotation axis around the [103] crystallographic direction (or around the c*) is derived. The data obtained with image integration taking into account only component 1 (including overlapped reflections) gave a structure solution, but the refinement was unsuccessful and the usual warning signs of twinning were present [low |E2 - 1| value (= 0.715), K high for reflections with low intensity, |Fo| > |Fc| with most of them belonging to the family of reflections with h = 3n, and high residual electron-density peaks]. Analysis of the data with PLATON suggests the same twin law as given above.
According to the twin law, reflections with h1 = 3n from the first crystallite overlap with reflections l2 = (2/3)h1 + l1 (where l2 is an integer) of the second crystallite, thereby explaining the fact that, for this family of reflections, |Fo| > |Fc|. These index relationships, taking into account the space group of the structure, also explain the observation by Merritt et al. that the h0l Weissenberg photograph for every third layer where h = 0, 6 or 12 consists of single spots, whereas otherwise the spots are doublets.
The final structural model for (I) emerged through refinement of data obtained using the TwinSolve data-reduction program (HKLF5 file containing merged reflections from component 1, plus only the overlapped reflections with component 2). The fractions are 0.370 (3) and 0.630 (3). This result classifies the studied crystal as a non-merohedral twin. It is worth mentioning that, using the HKLF5 file derived directly from TwinSolve, the PLATON method for twin law derivation is by-passed. Thus, the geometrically derived law could serve as a very useful tool in the analysis of a structure from a twinned crystal. Fig. 1(b) presents a section of the reciprocal lattice showing clearly the overlap of peaks with h = 3n.
The structure of (I) consists of a ZnII cation, sitting on centre of symmetry, octahedrally coordinated (Fig. 2) by two deprotonated quinolin-8-olate ligands and two water molecules trans to each other in the equatorial and axial positions, respectively. Selected bond lengths and angles for all data sets are listed in Table 3. The Zn—O1 bond to the deprotonated hydroxy O atom and the Zn—N bond to the pyridine N atom of the quinolin-8-olate ligand are 2.062 (2) and 2.103 Å, respectivelly. The Zn—O2 bond, involving the water molecule, is 2.220 Å, slightly longer than Zn—O1, indicative of a weak zinc–water bond, resulting in easy dehydration (Merritt et al., 1954). These bond lengths are in agreement, within experimental error, amongst themselves in the three data sets [Table 3; present study, Merritt et al. (1954) and Palenik (1964)], but they differ significantly from the corresponding values of the fourth set (Table 3; Chen et al., 2003). The difference is largest for the bond length to water atom O2; Chen et al. report a value of 2.451 Å for this bond. The bond length and angle values given by Chen et al. (Table 3), together with the published unit-cell dimensions (Table 2), are closer to the corresponding values of the analogous CuII compound (Okabe & Saishu, 2001; Tables 2 and 3). Both compounds, viz. [Zn(C9H6NO)2(H2O)2] and [Cu(C9H6NO)2(H2O)2], are isostructural. The axial distortion in octahedrally coordinated CuII compounds is characteristic of the Jahn–Teller effect (Feng et al., 2007). A systematic search of the CSD shows that the values derived from the three data sets [Table 3; present study, Merritt et al. (1954) and Palenik (1964)] are characteristic of ZnII compounds and those of the fourth data set are characteristic of CuII compounds. Furthermore, in the checkCIF report concerning Chen's study, an Alert comment is reported, related to the Hirshfeld test for the wrong assignment of atom species.
Another issue concerning the present structure is related to hydrogen-bond formation, which is adequately described in all previous papers. Merritt et al. (1954) ruled out the possibility of hydrogen-bond formation, based on the observation that (i) the intermolecular distances between adjacent water molecules and the closest approach of the C atoms are too long, and (ii) they did not take into account the possibility of hydrogen-bond formation between the coordinated water of one molecule and the deprotonated hydroxy O atom of the quinolin-8-olate ligand of an adjacent complex. Palenik (1964) did discuss this possibility, and Chen et al. (2003) discussed hydrogen-bond formation in an incorrect way. Finally, Okabe & Saishu (2001), in their study of the isostructural compound with CuII, reported the correct hydrogen-bond paths and values, but they did not discuss at all the network arising through those hydrogen bonds. The H atoms of the coordinated water molecules form hydrogen bonds (Table 4) with the deprotonated O atoms of the quinolin-8-olate ligands of neighbouring complexes, thereby giving rise to layers parallel to the (001) crystallographic plane (Fig. 3).
Data collection: CrystalClear (Rigaku/MSC, 2005); cell refinement: TwinSolve (Rigaku/MSC, 2002); data reduction: TwinSolve (Rigaku/MSC, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Crystal Impact, 2012); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).
[Zn(C9H6NO)2(H2O)2] | F(000) = 400 |
Mr = 389.70 | Dx = 1.701 Mg m−3 |
Monoclinic, P21/a | Cu Kα radiation, λ = 1.54178 Å |
Hall symbol: -P 2yab | Cell parameters from 15184 reflections |
a = 11.1132 (4) Å | θ = 2.5–70.0° |
b = 5.4109 (2) Å | µ = 2.49 mm−1 |
c = 13.1888 (5) Å | T = 160 K |
β = 106.370 (2)° | Plate, pale yellow |
V = 760.92 (5) Å3 | 0.22 × 0.09 × 0.04 mm |
Z = 2 |
Rigaku R-AXIS SPIDER image-plate diffractometer | 1289 independent reflections |
Radiation source: fine-focus sealed tube | 1171 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.000 |
θ scans | θmax = 65.0°, θmin = 3.5° |
Absorption correction: multi-scan (TwinSolve; Rigaku/MSC, 2002) | h = 0→13 |
Tmin = 0.669, Tmax = 1.000 | k = 0→6 |
1289 measured reflections | l = −15→14 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.034 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.091 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.15 | w = 1/[σ2(Fo2) + (0.0248P)2 + 2.2136P] where P = (Fo2 + 2Fc2)/3 |
1289 reflections | (Δ/σ)max = 0.009 |
124 parameters | Δρmax = 0.28 e Å−3 |
0 restraints | Δρmin = −0.33 e Å−3 |
[Zn(C9H6NO)2(H2O)2] | V = 760.92 (5) Å3 |
Mr = 389.70 | Z = 2 |
Monoclinic, P21/a | Cu Kα radiation |
a = 11.1132 (4) Å | µ = 2.49 mm−1 |
b = 5.4109 (2) Å | T = 160 K |
c = 13.1888 (5) Å | 0.22 × 0.09 × 0.04 mm |
β = 106.370 (2)° |
Rigaku R-AXIS SPIDER image-plate diffractometer | 1289 independent reflections |
Absorption correction: multi-scan (TwinSolve; Rigaku/MSC, 2002) | 1171 reflections with I > 2σ(I) |
Tmin = 0.669, Tmax = 1.000 | Rint = 0.000 |
1289 measured reflections |
R[F2 > 2σ(F2)] = 0.034 | 0 restraints |
wR(F2) = 0.091 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.15 | Δρmax = 0.28 e Å−3 |
1289 reflections | Δρmin = −0.33 e Å−3 |
124 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Zn1 | 0.0000 | 0.0000 | 0.0000 | 0.0123 (2) | |
O1 | −0.0873 (2) | −0.2534 (5) | 0.07268 (19) | 0.0154 (5) | |
N1 | 0.0804 (3) | 0.1112 (5) | 0.1573 (2) | 0.0140 (7) | |
C1 | 0.1580 (3) | 0.2930 (7) | 0.1968 (3) | 0.0171 (8) | |
H1 | 0.1840 | 0.3995 | 0.1497 | 0.022* | |
C2 | 0.2046 (3) | 0.3366 (7) | 0.3074 (3) | 0.0199 (9) | |
H2 | 0.2604 | 0.4700 | 0.3333 | 0.026* | |
C3 | 0.1681 (3) | 0.1840 (7) | 0.3757 (3) | 0.0203 (9) | |
H3 | 0.1996 | 0.2088 | 0.4498 | 0.026* | |
C4 | 0.0381 (4) | −0.1749 (7) | 0.4009 (3) | 0.0201 (9) | |
H4 | 0.0668 | −0.1599 | 0.4756 | 0.026* | |
C5 | −0.0471 (4) | −0.3544 (7) | 0.3554 (3) | 0.0220 (9) | |
H5 | −0.0776 | −0.4626 | 0.3992 | 0.029* | |
C6 | −0.0902 (3) | −0.3813 (7) | 0.2450 (3) | 0.0181 (8) | |
H6 | −0.1498 | −0.5067 | 0.2161 | 0.024* | |
C7 | −0.0488 (3) | −0.2321 (7) | 0.1775 (3) | 0.0126 (7) | |
C8 | 0.0401 (3) | −0.0401 (6) | 0.2248 (3) | 0.0142 (8) | |
C9 | 0.0830 (3) | −0.0117 (7) | 0.3357 (3) | 0.0159 (8) | |
O2 | 0.1509 (2) | −0.2717 (5) | 0.0034 (2) | 0.0215 (6) | |
H7 | 0.133 (5) | −0.421 (10) | −0.021 (4) | 0.035 (14)* | |
H8 | 0.230 (4) | −0.267 (8) | 0.026 (3) | 0.018 (11)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Zn1 | 0.0130 (3) | 0.0101 (3) | 0.0130 (4) | −0.0036 (3) | 0.0025 (3) | −0.0001 (3) |
O1 | 0.0178 (13) | 0.0123 (12) | 0.0149 (13) | −0.0029 (11) | 0.0026 (10) | 0.0000 (11) |
N1 | 0.0145 (15) | 0.0078 (14) | 0.0201 (17) | −0.0006 (12) | 0.0053 (12) | −0.0019 (13) |
C1 | 0.0138 (17) | 0.0138 (19) | 0.021 (2) | 0.0013 (15) | 0.0013 (15) | 0.0009 (15) |
C2 | 0.0141 (17) | 0.0148 (18) | 0.027 (2) | 0.0006 (15) | −0.0006 (15) | −0.0052 (16) |
C3 | 0.0189 (18) | 0.019 (2) | 0.019 (2) | 0.0056 (17) | −0.0020 (15) | −0.0038 (16) |
C4 | 0.0228 (19) | 0.022 (2) | 0.015 (2) | 0.0043 (17) | 0.0054 (15) | 0.0007 (16) |
C5 | 0.0195 (18) | 0.023 (2) | 0.025 (2) | 0.0009 (17) | 0.0089 (17) | 0.0061 (17) |
C6 | 0.0128 (17) | 0.0190 (19) | 0.023 (2) | −0.0016 (16) | 0.0052 (15) | 0.0027 (16) |
C7 | 0.0076 (15) | 0.0108 (17) | 0.0176 (19) | 0.0017 (14) | 0.0008 (13) | −0.0033 (15) |
C8 | 0.0146 (17) | 0.0109 (18) | 0.017 (2) | 0.0049 (14) | 0.0046 (14) | −0.0009 (15) |
C9 | 0.0174 (18) | 0.0152 (18) | 0.016 (2) | 0.0045 (16) | 0.0057 (14) | −0.0021 (16) |
O2 | 0.0134 (13) | 0.0103 (13) | 0.0390 (17) | 0.0000 (11) | 0.0046 (12) | −0.0068 (13) |
Zn1—O1 | 2.065 (2) | C3—C9 | 1.419 (5) |
Zn1—O1i | 2.065 (2) | C3—H3 | 0.9500 |
Zn1—N1 | 2.102 (3) | C4—C5 | 1.371 (6) |
Zn1—N1i | 2.102 (3) | C4—C9 | 1.417 (5) |
Zn1—O2 | 2.221 (3) | C4—H4 | 0.9500 |
Zn1—O2i | 2.221 (3) | C5—C6 | 1.406 (5) |
O1—C7 | 1.332 (4) | C5—H5 | 0.9500 |
N1—C1 | 1.315 (5) | C6—C7 | 1.373 (5) |
N1—C8 | 1.374 (5) | C6—H6 | 0.9500 |
C1—C2 | 1.422 (5) | C7—C8 | 1.448 (5) |
C1—H1 | 0.9500 | C8—C9 | 1.413 (5) |
C2—C3 | 1.365 (6) | O2—H7 | 0.87 (5) |
C2—H2 | 0.9500 | O2—H8 | 0.84 (4) |
O1—Zn1—O1i | 180.0 | C2—C3—C9 | 119.8 (3) |
O1—Zn1—N1 | 81.76 (10) | C2—C3—H3 | 120.1 |
O1i—Zn1—N1 | 98.25 (10) | C9—C3—H3 | 120.1 |
O1—Zn1—N1i | 98.24 (10) | C5—C4—C9 | 119.6 (4) |
O1i—Zn1—N1i | 81.76 (10) | C5—C4—H4 | 120.2 |
N1—Zn1—N1i | 180.0 | C9—C4—H4 | 120.2 |
O1—Zn1—O2 | 90.11 (10) | C4—C5—C6 | 121.2 (4) |
O1i—Zn1—O2 | 89.89 (10) | C4—C5—H5 | 119.4 |
N1—Zn1—O2 | 93.50 (11) | C6—C5—H5 | 119.4 |
N1i—Zn1—O2 | 86.50 (11) | C7—C6—C5 | 122.1 (4) |
O1—Zn1—O2i | 89.89 (10) | C7—C6—H6 | 118.9 |
O1i—Zn1—O2i | 90.11 (10) | C5—C6—H6 | 118.9 |
N1—Zn1—O2i | 86.50 (11) | O1—C7—C6 | 123.6 (3) |
N1i—Zn1—O2i | 93.50 (11) | O1—C7—C8 | 119.3 (3) |
O2—Zn1—O2i | 180.0 | C6—C7—C8 | 117.1 (3) |
C7—O1—Zn1 | 111.6 (2) | N1—C8—C9 | 122.0 (3) |
C1—N1—C8 | 119.0 (3) | N1—C8—C7 | 117.1 (3) |
C1—N1—Zn1 | 130.9 (3) | C9—C8—C7 | 120.9 (3) |
C8—N1—Zn1 | 110.1 (2) | C8—C9—C4 | 119.1 (3) |
N1—C1—C2 | 122.6 (4) | C8—C9—C3 | 117.4 (3) |
N1—C1—H1 | 118.7 | C4—C9—C3 | 123.5 (3) |
C2—C1—H1 | 118.7 | Zn1—O2—H7 | 121 (3) |
C3—C2—C1 | 119.1 (3) | Zn1—O2—H8 | 134 (3) |
C3—C2—H2 | 120.5 | H7—O2—H8 | 106 (4) |
C1—C2—H2 | 120.5 |
Symmetry code: (i) −x, −y, −z. |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H7···O1ii | 0.87 (5) | 1.91 (5) | 2.777 (4) | 178 |
O2—H8···O1iii | 0.85 (5) | 1.95 (5) | 2.796 (3) | 177 |
Symmetry codes: (ii) −x, −y−1, −z; (iii) x+1/2, −y−1/2, z. |
Experimental details
Crystal data | |
Chemical formula | [Zn(C9H6NO)2(H2O)2] |
Mr | 389.70 |
Crystal system, space group | Monoclinic, P21/a |
Temperature (K) | 160 |
a, b, c (Å) | 11.1132 (4), 5.4109 (2), 13.1888 (5) |
β (°) | 106.370 (2) |
V (Å3) | 760.92 (5) |
Z | 2 |
Radiation type | Cu Kα |
µ (mm−1) | 2.49 |
Crystal size (mm) | 0.22 × 0.09 × 0.04 |
Data collection | |
Diffractometer | Rigaku R-AXIS SPIDER image-plate diffractometer |
Absorption correction | Multi-scan (TwinSolve; Rigaku/MSC, 2002) |
Tmin, Tmax | 0.669, 1.000 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 1289, 1289, 1171 |
Rint | 0.000 |
(sin θ/λ)max (Å−1) | 0.588 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.034, 0.091, 1.15 |
No. of reflections | 1289 |
No. of parameters | 124 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.28, −0.33 |
Computer programs: CrystalClear (Rigaku/MSC, 2005), TwinSolve (Rigaku/MSC, 2002), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Crystal Impact, 2012).
Space group | a (Å) | b (Å) | c (Å) | β (°) | V (Å3) | -a/(ccosβ)g | Reference |
P21/aa | 11.28 | 5.42 | 13.16 | 106.3 | 772.23 | 3.05 | (a) |
P21/cb | 13.16 | 5.42 | 11.28 | 106.3 | 772.23 | (b) | |
P21/cc | 12.955 | 5.546 | 11.423 | 106.288 | 786.8 | (c) | |
P21/ad | 11.423 | 5.546 | 12.955 | 106.288 | 786.8 | 3.14 | (d) |
P21/ae | 11.425 | 5.542 | 12.950 | 106.39 | 786.7 | (e) | |
P21/af | 11.1134 | 5.4112 | 13.1906 | 106.371 | 761.08 | 2.99 | (f) |
References: (a) Merritt et al. (1954); (b) Palenik (1964); (c) Chen (2003); (d) same as in (c) but with a and c axes interchanged in order to mach the space-group change; (e) Okabe & Saishu (2001); (f) this work; (g) for an explanation of this relation, see text. |
Parameter | Compound? | Compound? | Compound? | Compound? | Compound? |
Zn—O1 | 2.05 | 2.066 | 1.966 (2) | 1.966 (2) | 2.065 (2) |
Zn—N1 | 2.06 | 2.099 | 2.011 (2) | 2.013 (2) | 2.102 (3) |
Zn1—O2 | 2.27 | 2.263 | 2.451 (2) | 2.451 (2) | 2.221 (3) |
N1—Zn1—O2 | 87.3 | 86.7 | 86.61 (8) | 86.33 (6) | 86.5 (1) |
O1—Zn1—O2 | 85.4 | 89.2 | 89.25 (8) | 89.12 (6) | 89.9 (1) |
N1—Zn1—O1 | 79.8 | 81.5 | 83.87 (9) | 83.70 (6) | 81.8 (1) |
References:(a) Merritt et al. (1954); (b) Palenik (1964); (c) Chen et al. (2003); (d) Okabe & Saishu (2001); (e) this work. |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H7···O1i | 0.87 (5) | 1.91 (5) | 2.777 (4) | 178 |
O2—H8···O1ii | 0.85 (5) | 1.95 (5) | 2.796 (3) | 177 |
Symmetry codes: (i) −x, −y−1, −z; (ii) x+1/2, −y−1/2, z. |