Two different one-dimensional Cd^II halide coordination polymers constructed through bridging carboxyl­ate ligands

Two cadmium halide complexes, catena-poly[[chlorido­cadmium(II)]-di-μ-chlorido-[chlorido­cadmium(II)]-bis­[μ₂-4-(di­methyl­amino)­pyridin-1-ium-1-acetate]-κ³O:O,O′;κ³O,O′:O], [CdCl₂(C₉H₁₂N₂O₂)]_n, (I), and catena-poly[1-cyano­methyl-1,4-diazonia­bi­cyclo­[2.2.2]octane [[di­chlorido­cadmium(II)]-μ-oxalato-κ⁴O¹,O²:O^1′,O^2′] monohydrate], {(C₈H₁₅N₃)[CdCl₂(C₂O₄)]·H₂O}_n, (II), were synthesized in aqueous solution. In (I), the Cd^II cation is octa­hedrally coordinated by three O atoms from two carboxyl­ate groups and by one terminal and two bridging chloride ligands. Neighbouring Cd^II cations are linked together by chloride anions and bridging O atoms to form a one-dimensional zigzag chain. Hydrogen-bond inter­actions are involved in the formation of the two-dimensional network. In (II), each Cd^II cation is octa­hedrally coordinated by four O atoms from two oxalic acid ligands and two terminal Cl⁻ ligands. Neighbouring Cd^II cations are linked together by oxalate groups to form a one-dimensional anionic chain, and the water mol­ecules and organic cations are connected to this one-dimensional zigzag chain through hydrogen-bond inter­actions.

S1. Introduction

\ Extensive attention has been concentrated on the crystal engineering of new dielectric and ferroelectric materials in recent years, owing to their novel structural characteristics and potential applications, for instance as filters, capacitors, resonators, switchable nonlinear optical devices or solid-state transducer components in microwave communication systems (Vanderah, 2002; Fu et al., 2008; Ye et al., 2013; Shi et al., 2014). In the search for potential ferroelectric materials, molecular-based one-, two- and three-dimensional cadmium(II) organic–inorganic compounds have been of inter­est as they often display solid–solid phase transitions induced by a variation in temperature (Zhou et al., 2013; Liao & Zhang, 2013). Many reports have been devoted to the formation of infinite polymeric frameworks through carboxyl­ate bridging ligands (Zhang et al., 2012; Wang et al., 2012; Nie & Wang, 2011). According to the literature [References?], carb­oxy­lic acid and nitro­gen bridging ligands with different coordinating characters are excellent candidates for the construction of novel highly connected topological frameworks. The structural topologies of these polymers are affected by the coordination geometries of the organic ligands and the metal atoms involved. Bridging ligands with N– and O-donor atoms play an instructive role in building coordination polymers. Among the various ligands, the versatile carb­oxy­lic acid ligands showing diverse coordination modes, especially for aromatic carb­oxy­lic acids, such as benzene- and naphthalene-based carb­oxy­lic acids, have been used and well documented in the preparation of numerous carboxyl­ate-containing coordination complexes [References?]. In the present paper, we report two one-dimensional coordination polymers which exhibit inter­esting structural features. These are catena-poly[[chloridocadmium(II)]-di-µ-chlorido-[chloridocadmium(II)]- bis­[µ₂-4-(di­methyl­amino)­pyridin-1-ium-1-acetate]-κ³O:O,\ O';κ³O,O':O], (I), and catena-poly[1-cyano­methyl-1,4-diazo­niabi­cyclo­[2.2.2]o­ctane [[dichloridocadmium(II)]-µ-oxalato-κ⁴O¹,O²:O^1',\ O^2'] monohydrate], (II).

S2. Experimental

S2.1. Synthesis and crystallization

4-(Di­methyl­amino)­pyridin-1-ium-1-acetate was prepared according to the literature procedure of Wei et al. (1997). An aqueous solution (15 ml) of 4-(di­methyl­amino)­pyridin-1-ium-1-acetate (0.725 g, 4 mmol) was added slowly to an aqueous solution containing cadmium chloride (0.733 g, 4 mmol), affording a colourless solution. Upon standing at room temperature for several days, suitable colourless single crystals of (I) were obtained by slow solvent evaporation.

1-Cyano­methyl-4-aza-1-azoniabi­cyclo­[2.2.2]o­ctane chloride was prepared according to the literature procedures of Li et al. (2015). An aqueous solution (20 ml) of 1-cyano­methyl-4-aza-1-azoniabi­cyclo­[2.2.2]o­ctane chloride (0.750 g, 4 mmol) was added slowly to an aqueous solution containing cadmium chloride (0.456 g, 2 mmol) and oxalic acid dihydrate (0.252 g, 2 mmol), affording a colourless solution. Upon standing at room temperature for several days, suitable colourless single crystals of (II) were obtained by slow solvent evaporation.

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. C-bound H atoms were included in calculated positions and refined using a riding model, with C—H = 0.93 (pyridine), 0.96 (methyl) or 0.97 Å (methyl­ene), and with U_iso(H) = 1.2U_eq(C) for pyridine and methyl­ene H atoms, and 1.5U_eq(C) for methyl H atoms [Added text OK?]. The water H atoms were located in a difference Fourier synthesis and treated by a mixture of independent and constrained refinement, with O—H and H···H distance restraints of 0.82 (1) and 1.39 (1) Å, respectively.

S3. Results and discussion

\ The asymmetric unit of complex (I) contains one Cd^II cation, two chloride ligands and one 4-(di­methyl­amino)­pyridin-1-ium-1-acetate (L) ligand (Fig. 1). As shown in Fig. 1, the central Cd^II cation is six-coordinated by three O atoms, O1, O1ⁱ and O2ⁱ (see Table 2 for geometric parameters and symmetry codes), from two different L carboxyl­ate groups, one terminal Cl2 and two bridging chloride anions (Cl1 and Cl1ⁱⁱ). The Cd^II centre adopts a distorted CdO₃Cl₃ o­cta­hedral coordination geometry, brought about mainly by the small bite angles [O1—Cd1—O2 = 53.73 (7)°] of the bidentate carboxyl­ate groups (Table 2). The carboxyl O atoms of the L ligands are coordinated to two different Cd^II cations. Each Cd^II cation is joined to neighbouring Cd^II cations through double chloride bridges and monodentate carboxyl­ate groups of L ligands. The Cd—O1/O2 bond lengths range from 2.337 (2) to 2.519 (2) Å and the terminal Cd—Cl2 distance is 2.4621 (9) Å, while the Cd—µ₂-Cl1 bond lengths are 2.5476 (8) and 2.6457 (8) Å. Thus, the order of the Cd—Cl distances is clearly differentiated as µ₂-Cl > terminal Cl. In general, all the bond lengths and angles are in the normal ranges for those in other Cd^II compounds (Inomata et al., 2004).

Compound (I) displays a novel coordination architecture compared with the similar compound [CdCl₂(Hpipe-4)], (III) (Hpipe-4 is ????; Inomata et al., 2004), in which the central Cd^II cation is in a distorted o­cta­hedral geometry coordinated by two carboxyl­ate O atoms and four bridging Cl atoms, rather than three O atoms of two carboxyl­ate groups, plus one terminal and two bridging chloride anions. It should be pointed out that the structure of (III) consists of a one-dimensional polymer chain bridged only by symmetry-related Cl atoms. This is different from the case of (I), in which the metal atoms are bridged by symmetry-related Cl atoms and O atoms of the carboxyl­ate groups, forming a one-dimensional polymer chain.

In the structure of (I), the corrugated one-dimensional polymer chain has re­cta­ngular Cd₂(Cl)₂ rings and diamond-shaped Cd₂(O)₂ rings with additional L ligands, extending in the direction of the c axis like a twisted zigzag screen, with a Cd···Cd···Cd bond angle of 155.4 (4)°. The Cd···Cd distance across the bridging Cl atom is 3.821 (9) Å, while the longest Cd···Cd contact across the carboxyl­ate group is 4.125 (1) Å. These twisted zigzag chains are linked into a layer structure in the bc plane via weak π–π inter­actions between the pyridine rings, with an inter­planar distance of 3.888 (5) Å (Fig. 2).

The crystal structure of (I) exhibits two distinct metal-atom coordination modes: one can be described as bidentate chelating and monodentate carboxyl­ate groups, and the other can be described as terminal and bridging chlorides. This is different from what we found in our previous report on catena-poly[1-carb­oxy­methyl-4-(di­methyl­amino)­pyridinium [cadmium(II)-tri-µ-thio­cyanato-κ⁴N:S;κ²S:N] [[[4-(di­methyl­amino)­pyridinium-1-acetate-κ²O,O']cadmium(II)]\ -di-µ-thio­cyanato-κ²N:S;κ²S:N]] (Wang & Zhou, 2015), where the carboxyl­ate group exhibits only the bidentate chelating coordination mode. Polymer (I) can thus be considered as the first example of a cadmium–halide/carboxyl­ate complex having various coordination modes. To the best of our knowledge, this distinct type of coordination polymer involving chloride ligands and bidentate chelating and monodentate carboxyl­ate groups has not been reported previously.

In addition to π–π inter­actions between the pyridine rings, the main inter­molecular inter­actions in (I) are C2—H2···Cl2 and C5—H5···O2 hydrogen-bond inter­actions linking the L ligands and terminal Cl atoms (Fig. 3 and Table 3). Adjacent coordination polymers are linked together via C2—H2···Cl2^? [Please provide missing symmetry code] hydrogen bonds to form a two-dimensional network in the bc plane.

Complex (II) contains one Cd^II cation, one oxalate ligand, one 1-cyano­methyl-1,4-diazo­niabi­cyclo­[2.2.2]o­ctane cation (L'), two chloride ligands and one free water molecule (Fig. 4 and Table 4). As shown in Fig. 4, the central Cd^II cation is six-coordinated by four O atoms from two oxalate ligands and two terminal Cl ligands, adopting a distorted CdO₄Cl₂ o­cta­hedral coordination geometry. Each Cd^II cation is joined to neighbouring Cd^II cations through bridging bis-monodentate oxalate groups, and the organic cation is bonded to the oxalate groups through N1—H1···O2^? [Please provide missing symmetry code] hydrogen bonding. The Cd—O and Cd—Cl bond lengths are in good agreement with values found in other Cd^II complexes with a six-coordinate o­cta­hedral geometry (Inomata et al., 2004; Zhou et al., 2013). The tetra­dentate bridging oxalates chelate to the cadmium centres with different carboxyl­ate groups, forming five-membered CdC₂O₂ rings composed of atoms Cd1, C9, C9ⁱ, O3ⁱ and O4 [symmetry code: (i) −x, −y, −z + 1].

In contrast with the structure of (I), in (II) bridging bis-monodentate oxalate groups only exist between adjacent Cd^II cations to give a chain structure, with a Cd···Cd distance of 5.992 (9) Å. The metal atoms are linked by symmetry-related oxalate groups, forming a one-dimensional zigzag chain, with a Cd···Cd···Cd bond angle of 90.40 (5)°. Additionally, each water molecule is connected to two adjacent coordination polymers by means of O1W—H1A···O4, O1W—H1A···Cl2 and O1W—H1B···Cl1 hydrogen bonds (Fig. 5 and Table 5), forming a network.

Finally, our original inter­est in (I) and (II) lay mainly in their potential as molecular ferroelectric materials. The variable-temperature dielectric response, especially in the relatively high frequency range, is treated as an effective indicator of a structural phase transition. However, measurement of the dielectric properties of (I) and (II) with varying temperature did not reveal dielectric anomalies over the temperature range 83–393 K. This reveals that the two compounds might not undergo a distinct structural phase transition within this temperature range and so they are not ferroelectric materials like those reported earlier (Ye et al., 2009; Fu et al., 2008). Further phase-transition materials still need to be sought and explored, and related materials are currently being investigated for dielectric properties and ferroelectric activity.

Computing details

For both compounds, data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear (Rigaku, 2005); data reduction: CrystalClear (Rigaku, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. The coordination environment of the Cd^II cation in (I), with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms have been omitted for clarity. [Symmetry codes: (i) −x, −y + 1, −z + 1; (ii) −x, −y + 1, −z; (iii) x, y, z + 1.] [Please supply revised plot with full labelling of pyridine C and N atoms.]
	Fig. 2. A perspective view of the stacking of the infinite one-dimensional layer structure of (I), formed by the pyridine rings via π–π stacking interactions (dashed lines).
	Fig. 3. An illustration of the network of (I) along the a axis, showing the hydrogen-bonding interactions (dashed lines).
	Fig. 4. The coordination environment of the Cd^II cation in (II), with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms have been omitted for clarity. [The dashed line indicates a hydrogen bond?] [Symmetry codes: (i) −x, −y, −z + 1; (ii) −x + 1, −y, 1 − z; (iii) x − 1, y, z.] [Please supply revised plot with full labelling of pyridine C and N atoms.]
	Fig. 5. The crystal packing of (II), showing the hydrogen-bonding interactions (dashed lines) among the cationic ligands, water molecules and coordination polymers.

(I) catena-Poly[[chloridocadmium(II)]-di-µ-chlorido-[chloridocadmium(II)]-bis[µ₂-4-(dimethylamino)pyridin-1-ium-1-acetate]-κ³O:O,O';κ³O,O':O]

Crystal data

[CdCl2(C9H12N2O2)]	F(000) = 712
Mr = 363.51	Dx = 2.010 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2705 reflections
a = 10.273 (2) Å	θ = 3.4–27.5°
b = 15.081 (3) Å	µ = 2.25 mm^−1
c = 7.7654 (16) Å	T = 293 K
β = 93.06 (3)°	Block, colourless
V = 1201.3 (4) Å^3	0.23 × 0.20 × 0.20 mm
Z = 4

Data collection

Rigaku SCXmini diffractometer	2389 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.026
Graphite monochromator	θmax = 27.5°, θmin = 3.4°
ω scans	h = −13→13
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	k = −19→18
Tmin = 0.626, Tmax = 0.662	l = −9→9
8199 measured reflections	3 standard reflections every 180 reflections
2705 independent reflections	intensity decay: none

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)] = 0.027	H-atom parameters constrained
wR(F^2) = 0.060	w = 1/[σ^2(Fo^2) + (0.0255P)^2 + 0.4338P] where P = (Fo^2 + 2Fc^2)/3
S = 1.16	(Δ/σ)max < 0.001
2705 reflections	Δρmax = 0.40 e Å^−3
147 parameters	Δρmin = −0.98 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008)
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0819 (12)

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
Cd1	0.031494 (18)	0.482011 (13)	0.24224 (2)	0.02572 (8)
Cl2	0.27032 (7)	0.48204 (5)	0.29061 (11)	0.03636 (17)
Cl1	−0.02696 (7)	0.61262 (4)	0.04490 (9)	0.03150 (15)
O1	−0.00217 (18)	0.59393 (13)	0.4736 (3)	0.0353 (5)
C8	0.1001 (2)	0.62695 (17)	0.5422 (3)	0.0247 (6)
N1	0.2953 (2)	0.72499 (13)	0.5061 (3)	0.0231 (5)
C7	0.1716 (2)	0.69114 (17)	0.4287 (3)	0.0253 (6)
H7A	0.1888	0.6615	0.3214	0.030*
H7B	0.1148	0.7411	0.4008	0.030*
N2	0.6425 (2)	0.82156 (16)	0.7260 (3)	0.0326 (5)
C4	0.4290 (3)	0.84663 (17)	0.5900 (4)	0.0295 (6)
H4	0.4398	0.9078	0.5968	0.035*
C2	0.5078 (3)	0.69823 (18)	0.6287 (4)	0.0292 (6)
H2	0.5721	0.6576	0.6632	0.035*
C3	0.5311 (2)	0.79042 (18)	0.6510 (3)	0.0248 (6)
C5	0.3157 (3)	0.81287 (17)	0.5217 (4)	0.0262 (6)
H5	0.2496	0.8516	0.4844	0.031*
C1	0.3926 (3)	0.66909 (17)	0.5577 (4)	0.0284 (6)
H1	0.3799	0.6084	0.5438	0.034*
C6	0.7460 (3)	0.7622 (2)	0.7917 (4)	0.0420 (8)
H6A	0.7093	0.7163	0.8597	0.063*
H6B	0.8086	0.7952	0.8619	0.063*
H6C	0.7882	0.7361	0.6967	0.063*
C9	0.6632 (3)	0.9167 (2)	0.7448 (5)	0.0472 (8)
H9A	0.6717	0.9428	0.6333	0.071*
H9B	0.7412	0.9272	0.8154	0.071*
H9C	0.5902	0.9427	0.7983	0.071*
O2	0.1422 (2)	0.60966 (14)	0.6910 (2)	0.0357 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cd1	0.02282 (11)	0.03089 (12)	0.02344 (12)	−0.00546 (8)	0.00115 (8)	0.00155 (8)
Cl2	0.0238 (3)	0.0330 (4)	0.0520 (5)	0.0002 (3)	−0.0009 (3)	0.0010 (3)
Cl1	0.0374 (4)	0.0288 (3)	0.0284 (3)	0.0005 (3)	0.0029 (3)	−0.0009 (3)
O1	0.0262 (10)	0.0400 (12)	0.0397 (12)	−0.0104 (8)	0.0014 (9)	0.0011 (9)
C8	0.0259 (13)	0.0241 (13)	0.0244 (14)	0.0000 (10)	0.0056 (11)	−0.0020 (11)
N1	0.0204 (10)	0.0229 (11)	0.0262 (12)	−0.0030 (9)	0.0017 (9)	0.0017 (9)
C7	0.0219 (13)	0.0285 (14)	0.0252 (14)	−0.0046 (10)	−0.0031 (11)	0.0020 (11)
N2	0.0253 (12)	0.0399 (14)	0.0324 (13)	−0.0074 (10)	−0.0009 (10)	−0.0053 (11)
C4	0.0299 (14)	0.0208 (13)	0.0381 (16)	−0.0019 (11)	0.0032 (12)	−0.0037 (12)
C2	0.0224 (13)	0.0291 (14)	0.0360 (16)	0.0032 (10)	−0.0008 (12)	0.0036 (12)
C3	0.0209 (12)	0.0319 (14)	0.0221 (13)	−0.0038 (10)	0.0050 (10)	−0.0014 (11)
C5	0.0238 (13)	0.0241 (13)	0.0309 (15)	0.0029 (10)	0.0039 (11)	0.0026 (11)
C1	0.0293 (14)	0.0212 (13)	0.0348 (16)	0.0003 (10)	0.0022 (12)	0.0015 (11)
C6	0.0281 (15)	0.057 (2)	0.0406 (18)	−0.0053 (14)	−0.0050 (13)	0.0062 (16)
C9	0.0369 (18)	0.0455 (19)	0.059 (2)	−0.0109 (14)	−0.0004 (16)	−0.0155 (17)
O2	0.0401 (12)	0.0442 (12)	0.0229 (10)	−0.0109 (9)	0.0028 (9)	0.0052 (9)

Geometric parameters (Å, º)

Cd1—O2^i	2.337 (2)	N2—C3	1.341 (3)
Cd1—Cl2	2.4621 (9)	N2—C9	1.456 (4)
Cd1—O1	2.502 (2)	N2—C6	1.461 (4)
Cd1—O1^i	2.519 (2)	C4—C5	1.353 (4)
Cd1—Cl1	2.5476 (8)	C4—C3	1.410 (4)
Cd1—Cl1^ii	2.6457 (8)	C4—H4	0.9300
Cd1—C8^i	2.752 (3)	C2—C1	1.352 (4)
Cl1—Cd1^ii	2.6457 (8)	C2—C3	1.420 (4)
O1—C8	1.255 (3)	C2—H2	0.9300
O1—Cd1^i	2.519 (2)	C5—H5	0.9300
C8—O2	1.240 (3)	C1—H1	0.9300
C8—C7	1.524 (4)	C6—H6A	0.9600
C8—Cd1^i	2.752 (3)	C6—H6B	0.9600
N1—C5	1.346 (3)	C6—H6C	0.9600
N1—C1	1.352 (3)	C9—H9A	0.9600
N1—C7	1.468 (3)	C9—H9B	0.9600
C7—H7A	0.9700	C9—H9C	0.9600
C7—H7B	0.9700	O2—Cd1^i	2.3372 (19)
O2^i—Cd1—Cl2	137.11 (6)	C8—C7—H7A	108.6
O2^i—Cd1—O1	95.94 (7)	N1—C7—H7B	108.6
Cl2—Cd1—O1	93.73 (5)	C8—C7—H7B	108.6
O2^i—Cd1—O1^i	53.73 (7)	H7A—C7—H7B	107.6
Cl2—Cd1—O1^i	91.79 (5)	C3—N2—C9	120.4 (3)
O1—Cd1—O1^i	69.52 (8)	C3—N2—C6	121.7 (2)
O2^i—Cd1—Cl1	115.62 (6)	C9—N2—C6	117.9 (2)
Cl2—Cd1—Cl1	107.01 (3)	C5—C4—C3	120.9 (2)
O1—Cd1—Cl1	82.71 (5)	C5—C4—H4	119.5
O1^i—Cd1—Cl1	147.48 (5)	C3—C4—H4	119.5
O2^i—Cd1—Cl1^ii	83.60 (6)	C1—C2—C3	120.4 (3)
Cl2—Cd1—Cl1^ii	95.81 (4)	C1—C2—H2	119.8
O1—Cd1—Cl1^ii	166.40 (5)	C3—C2—H2	119.8
O1^i—Cd1—Cl1^ii	119.71 (5)	N2—C3—C4	122.5 (3)
Cl1—Cd1—Cl1^ii	85.25 (3)	N2—C3—C2	122.0 (3)
O2^i—Cd1—C8^i	26.65 (7)	C4—C3—C2	115.5 (2)
Cl2—Cd1—C8^i	115.16 (6)	N1—C5—C4	122.1 (2)
O1—Cd1—C8^i	82.81 (7)	N1—C5—H5	118.9
O1^i—Cd1—C8^i	27.10 (7)	C4—C5—H5	118.9
Cl1—Cd1—C8^i	136.06 (6)	C2—C1—N1	122.4 (2)
Cl1^ii—Cd1—C8^i	101.74 (6)	C2—C1—H1	118.8
Cd1—Cl1—Cd1^ii	94.75 (3)	N1—C1—H1	118.8
C8—O1—Cd1	115.32 (16)	N2—C6—H6A	109.5
C8—O1—Cd1^i	86.85 (16)	N2—C6—H6B	109.5
Cd1—O1—Cd1^i	110.48 (8)	H6A—C6—H6B	109.5
O2—C8—O1	123.7 (2)	N2—C6—H6C	109.5
O2—C8—C7	121.2 (2)	H6A—C6—H6C	109.5
O1—C8—C7	115.1 (2)	H6B—C6—H6C	109.5
O2—C8—Cd1^i	57.69 (13)	N2—C9—H9A	109.5
O1—C8—Cd1^i	66.05 (14)	N2—C9—H9B	109.5
C7—C8—Cd1^i	177.16 (18)	H9A—C9—H9B	109.5
C5—N1—C1	118.6 (2)	N2—C9—H9C	109.5
C5—N1—C7	120.4 (2)	H9A—C9—H9C	109.5
C1—N1—C7	121.0 (2)	H9B—C9—H9C	109.5
N1—C7—C8	114.7 (2)	C8—O2—Cd1^i	95.66 (16)
N1—C7—H7A	108.6
O2^i—Cd1—Cl1—Cd1^ii	−80.56 (6)	Cd1—O1—C8—Cd1^i	−111.19 (13)
Cl2—Cd1—Cl1—Cd1^ii	94.64 (4)	C5—N1—C7—C8	−124.1 (3)
O1—Cd1—Cl1—Cd1^ii	−173.67 (5)	C1—N1—C7—C8	58.2 (3)
O1^i—Cd1—Cl1—Cd1^ii	−142.63 (8)	O2—C8—C7—N1	3.6 (4)
Cl1^ii—Cd1—Cl1—Cd1^ii	0.0	O1—C8—C7—N1	−176.3 (2)
C8^i—Cd1—Cl1—Cd1^ii	−102.00 (8)	Cd1^i—C8—C7—N1	69 (4)
O2^i—Cd1—O1—C8	144.06 (18)	C9—N2—C3—C4	−1.0 (4)
Cl2—Cd1—O1—C8	5.90 (18)	C6—N2—C3—C4	178.7 (3)
O1^i—Cd1—O1—C8	96.4 (2)	C9—N2—C3—C2	179.4 (3)
Cl1—Cd1—O1—C8	−100.79 (18)	C6—N2—C3—C2	−0.9 (4)
Cl1^ii—Cd1—O1—C8	−128.6 (2)	C5—C4—C3—N2	−177.1 (3)
C8^i—Cd1—O1—C8	120.81 (17)	C5—C4—C3—C2	2.5 (4)
O2^i—Cd1—O1—Cd1^i	47.64 (8)	C1—C2—C3—N2	177.8 (3)
Cl2—Cd1—O1—Cd1^i	−90.52 (7)	C1—C2—C3—C4	−1.8 (4)
O1^i—Cd1—O1—Cd1^i	0.0	C1—N1—C5—C4	−1.2 (4)
Cl1—Cd1—O1—Cd1^i	162.79 (7)	C7—N1—C5—C4	−179.0 (2)
Cl1^ii—Cd1—O1—Cd1^i	134.95 (16)	C3—C4—C5—N1	−1.1 (4)
C8^i—Cd1—O1—Cd1^i	24.39 (7)	C3—C2—C1—N1	−0.4 (4)
Cd1—O1—C8—O2	−108.2 (3)	C5—N1—C1—C2	2.0 (4)
Cd1^i—O1—C8—O2	3.0 (3)	C7—N1—C1—C2	179.7 (3)
Cd1—O1—C8—C7	71.6 (2)	O1—C8—O2—Cd1^i	−3.2 (3)
Cd1^i—O1—C8—C7	−177.2 (2)	C7—C8—O2—Cd1^i	176.9 (2)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···Cl2^iii	0.93	2.67	3.582 (3)	167
C5—H5···O2^iv	0.93	2.55	3.263 (3)	134

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

(II) catena-Poly[1-cyanomethyl-1,4-diazoniabicyclo[2.2.2]octane [[dichloridocadmium(II)]-µ-oxalato-κ⁴O¹,O²:O^1',O^2'] monohydrate]

Crystal data

(C8H15N3)[CdCl2(C2O4)]·H2O	F(000) = 880
Mr = 442.57	Dx = 1.909 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3518 reflections
a = 8.4937 (17) Å	θ = 3.1–27.5°
b = 8.2364 (16) Å	µ = 1.79 mm^−1
c = 22.015 (4) Å	T = 293 K
β = 91.57 (3)°	Block, colourless
V = 1539.5 (5) Å^3	0.24 × 0.23 × 0.21 mm
Z = 4

Data collection

Rigaku SCXmini diffractometer	2866 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.042
Graphite monochromator	θmax = 27.5°, θmin = 3.1°
ω scans	h = −11→10
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	k = −10→8
Tmin = 0.674, Tmax = 0.705	l = −18→28
10055 measured reflections	3 standard reflections every 180 reflections
3518 independent reflections	intensity decay: none

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.054	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.150	H atoms treated by a mixture of independent and constrained refinement
S = 1.08	w = 1/[σ^2(Fo^2) + (0.060P)^2 + 9.8P] where P = (Fo^2 + 2Fc^2)/3
3518 reflections	(Δ/σ)max < 0.001
193 parameters	Δρmax = 1.02 e Å^−3
3 restraints	Δρmin = −1.21 e Å^−3

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
Cd1	0.24393 (5)	−0.02846 (6)	0.40479 (2)	0.02987 (17)
Cl1	0.2663 (2)	−0.2561 (3)	0.33064 (9)	0.0514 (5)
Cl2	0.1598 (3)	0.2020 (3)	0.33618 (10)	0.0655 (7)
O1	0.6200 (6)	0.1686 (6)	0.5128 (2)	0.0452 (13)
O2	0.4828 (5)	0.1000 (6)	0.42967 (19)	0.0331 (10)
O3	−0.0122 (6)	0.1356 (7)	0.5609 (2)	0.0460 (14)
O4	0.1657 (6)	0.1219 (7)	0.4893 (2)	0.0485 (14)
C9	0.0433 (7)	0.0731 (9)	0.5142 (3)	0.0316 (14)
C10	0.5300 (7)	0.0788 (8)	0.4844 (3)	0.0303 (14)
N1	0.3777 (7)	0.6397 (7)	0.6182 (3)	0.0331 (12)
H1	0.431 (9)	0.717 (10)	0.606 (3)	0.040*
N2	0.2470 (5)	0.3892 (6)	0.6574 (2)	0.0240 (10)
N3	0.3535 (10)	0.0014 (8)	0.6992 (4)	0.058 (2)
C1	0.4135 (11)	0.5004 (10)	0.5786 (3)	0.049 (2)
H1C	0.5262	0.4812	0.5793	0.059*
H1D	0.3798	0.5244	0.5371	0.059*
C2	0.3307 (10)	0.3528 (9)	0.6003 (3)	0.0430 (18)
H2A	0.4064	0.2663	0.6076	0.052*
H2B	0.2554	0.3164	0.5693	0.052*
C4	0.2050 (9)	0.6692 (9)	0.6186 (4)	0.050 (2)
H4B	0.1645	0.6870	0.5775	0.060*
H4C	0.1826	0.7648	0.6426	0.060*
C3	0.1266 (8)	0.5190 (10)	0.6462 (5)	0.053 (2)
H3A	0.0786	0.5483	0.6842	0.064*
H3B	0.0445	0.4790	0.6186	0.064*
C5	0.4386 (8)	0.6057 (9)	0.6808 (3)	0.0374 (16)
H5A	0.4122	0.6948	0.7074	0.045*
H5B	0.5524	0.5955	0.6807	0.045*
C6	0.3672 (8)	0.4507 (9)	0.7036 (3)	0.0336 (15)
H6A	0.3171	0.4704	0.7420	0.040*
H6B	0.4489	0.3698	0.7102	0.040*
C7	0.1602 (8)	0.2427 (8)	0.6807 (3)	0.0340 (15)
H7A	0.1085	0.2707	0.7180	0.041*
H7B	0.0800	0.2100	0.6510	0.041*
C8	0.2695 (9)	0.1074 (9)	0.6921 (3)	0.0392 (16)
O1W	0.1737 (17)	0.4808 (11)	0.4612 (5)	0.148 (5)
H1A	0.1892	0.3929	0.4448	0.222*
H1B	0.2023	0.5546	0.4390	0.222*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cd1	0.0244 (2)	0.0393 (3)	0.0260 (2)	−0.0055 (2)	0.00296 (16)	−0.0035 (2)
Cl1	0.0379 (9)	0.0613 (13)	0.0552 (11)	0.0046 (8)	0.0033 (8)	−0.0250 (10)
Cl2	0.0707 (14)	0.0750 (17)	0.0516 (12)	0.0379 (12)	0.0128 (10)	0.0201 (11)
O1	0.056 (3)	0.038 (3)	0.040 (3)	−0.018 (2)	−0.011 (2)	0.009 (2)
O2	0.035 (2)	0.035 (3)	0.030 (2)	−0.011 (2)	−0.0050 (18)	0.010 (2)
O3	0.038 (3)	0.062 (4)	0.039 (3)	−0.021 (2)	0.014 (2)	−0.024 (2)
O4	0.046 (3)	0.054 (4)	0.047 (3)	−0.024 (3)	0.019 (2)	−0.023 (3)
C9	0.029 (3)	0.039 (4)	0.027 (3)	−0.007 (3)	0.005 (2)	−0.003 (3)
C10	0.031 (3)	0.030 (4)	0.029 (3)	−0.005 (3)	0.000 (2)	0.002 (3)
N1	0.035 (3)	0.024 (3)	0.039 (3)	−0.009 (2)	−0.001 (2)	0.010 (2)
N2	0.023 (2)	0.019 (3)	0.029 (3)	−0.0006 (19)	−0.0014 (19)	0.001 (2)
N3	0.079 (5)	0.029 (4)	0.064 (5)	0.003 (3)	−0.013 (4)	0.009 (3)
C1	0.060 (5)	0.058 (6)	0.030 (4)	−0.011 (4)	0.012 (3)	0.001 (3)
C2	0.066 (5)	0.036 (4)	0.027 (3)	−0.011 (4)	0.009 (3)	−0.007 (3)
C4	0.038 (4)	0.030 (4)	0.082 (6)	−0.005 (3)	−0.007 (4)	0.015 (4)
C3	0.022 (3)	0.039 (5)	0.098 (7)	0.005 (3)	−0.001 (4)	0.024 (4)
C5	0.040 (4)	0.034 (4)	0.037 (4)	−0.012 (3)	−0.007 (3)	0.004 (3)
C6	0.037 (3)	0.037 (4)	0.027 (3)	−0.013 (3)	−0.004 (3)	0.000 (3)
C7	0.033 (3)	0.029 (4)	0.040 (4)	−0.012 (3)	−0.005 (3)	0.003 (3)
C8	0.054 (4)	0.027 (4)	0.036 (4)	−0.012 (3)	−0.006 (3)	0.003 (3)
O1W	0.222 (14)	0.077 (7)	0.139 (10)	−0.029 (7)	−0.085 (9)	0.010 (6)

Geometric parameters (Å, º)

Cd1—O3^i	2.303 (5)	N3—C8	1.136 (10)
Cd1—O2	2.340 (4)	C1—C2	1.490 (10)
Cd1—O4	2.346 (5)	C1—H1C	0.9700
Cd1—O1^ii	2.418 (5)	C1—H1D	0.9700
Cd1—Cl1	2.496 (2)	C2—H2A	0.9700
Cd1—Cl2	2.517 (2)	C2—H2B	0.9700
O1—C10	1.223 (8)	C4—C3	1.538 (10)
O1—Cd1^ii	2.418 (5)	C4—H4B	0.9700
O2—C10	1.271 (7)	C4—H4C	0.9700
O3—C9	1.253 (8)	C3—H3A	0.9700
O3—Cd1^i	2.303 (5)	C3—H3B	0.9700
O4—C9	1.255 (8)	C5—C6	1.506 (9)
C9—C9^i	1.535 (13)	C5—H5A	0.9700
C10—C10^ii	1.560 (13)	C5—H5B	0.9700
N1—C1	1.477 (10)	C6—H6A	0.9700
N1—C5	1.484 (8)	C6—H6B	0.9700
N1—C4	1.487 (9)	C7—C8	1.468 (10)
N1—H1	0.83 (8)	C7—H7A	0.9700
N2—C2	1.492 (8)	C7—H7B	0.9700
N2—C3	1.496 (8)	O1W—H1A	0.8207
N2—C6	1.508 (8)	O1W—H1B	0.8200
N2—C7	1.510 (8)
O3^i—Cd1—O2	147.11 (16)	C2—C1—H1D	109.7
O3^i—Cd1—O4	71.28 (17)	H1C—C1—H1D	108.2
O2—Cd1—O4	80.69 (17)	C1—C2—N2	110.2 (6)
O3^i—Cd1—O1^ii	88.05 (19)	C1—C2—H2A	109.6
O2—Cd1—O1^ii	69.31 (16)	N2—C2—H2A	109.6
O4—Cd1—O1^ii	78.3 (2)	C1—C2—H2B	109.6
O3^i—Cd1—Cl1	90.43 (13)	N2—C2—H2B	109.6
O2—Cd1—Cl1	114.32 (13)	H2A—C2—H2B	108.1
O4—Cd1—Cl1	160.59 (14)	N1—C4—C3	108.0 (6)
O1^ii—Cd1—Cl1	95.09 (14)	N1—C4—H4B	110.1
O3^i—Cd1—Cl2	104.75 (17)	C3—C4—H4B	110.1
O2—Cd1—Cl2	91.70 (13)	N1—C4—H4C	110.1
O4—Cd1—Cl2	89.76 (17)	C3—C4—H4C	110.1
O1^ii—Cd1—Cl2	158.82 (14)	H4B—C4—H4C	108.4
Cl1—Cd1—Cl2	101.50 (8)	N2—C3—C4	109.8 (6)
C10—O1—Cd1^ii	111.9 (4)	N2—C3—H3A	109.7
C10—O2—Cd1	114.1 (4)	C4—C3—H3A	109.7
C9—O3—Cd1^i	117.1 (4)	N2—C3—H3B	109.7
C9—O4—Cd1	115.7 (4)	C4—C3—H3B	109.7
O3—C9—O4	124.2 (6)	H3A—C3—H3B	108.2
O3—C9—C9^i	118.0 (7)	N1—C5—C6	109.7 (5)
O4—C9—C9^i	117.8 (7)	N1—C5—H5A	109.7
O1—C10—O2	125.2 (6)	C6—C5—H5A	109.7
O1—C10—C10^ii	119.0 (7)	N1—C5—H5B	109.7
O2—C10—C10^ii	115.7 (7)	C6—C5—H5B	109.7
C1—N1—C5	109.2 (6)	H5A—C5—H5B	108.2
C1—N1—C4	110.5 (6)	C5—C6—N2	109.3 (5)
C5—N1—C4	110.1 (6)	C5—C6—H6A	109.8
C1—N1—H1	106 (5)	N2—C6—H6A	109.8
C5—N1—H1	105 (5)	C5—C6—H6B	109.8
C4—N1—H1	115 (5)	N2—C6—H6B	109.8
C2—N2—C3	110.1 (6)	H6A—C6—H6B	108.3
C2—N2—C6	107.9 (5)	C8—C7—N2	110.6 (5)
C3—N2—C6	108.5 (6)	C8—C7—H7A	109.5
C2—N2—C7	111.9 (5)	N2—C7—H7A	109.5
C3—N2—C7	106.8 (5)	C8—C7—H7B	109.5
C6—N2—C7	111.5 (5)	N2—C7—H7B	109.5
N1—C1—C2	109.8 (6)	H7A—C7—H7B	108.1
N1—C1—H1C	109.7	N3—C8—C7	178.0 (8)
C2—C1—H1C	109.7	H1A—O1W—H1B	109.8
N1—C1—H1D	109.7
O3^i—Cd1—O2—C10	22.9 (7)	N1—C1—C2—N2	−4.0 (9)
O4—Cd1—O2—C10	54.4 (5)	C3—N2—C2—C1	60.9 (8)
O1^ii—Cd1—O2—C10	−26.5 (5)	C6—N2—C2—C1	−57.4 (8)
Cl1—Cd1—O2—C10	−112.7 (5)	C7—N2—C2—C1	179.5 (6)
Cl2—Cd1—O2—C10	143.9 (5)	C1—N1—C4—C3	63.3 (9)
O3^i—Cd1—O4—C9	2.5 (5)	C5—N1—C4—C3	−57.4 (9)
O2—Cd1—O4—C9	−160.1 (6)	C2—N2—C3—C4	−54.8 (9)
O1^ii—Cd1—O4—C9	−89.5 (6)	C6—N2—C3—C4	63.1 (9)
Cl1—Cd1—O4—C9	−17.9 (9)	C7—N2—C3—C4	−176.5 (7)
Cl2—Cd1—O4—C9	108.2 (5)	N1—C4—C3—N2	−5.6 (10)
Cd1^i—O3—C9—O4	177.7 (6)	C1—N1—C5—C6	−57.3 (8)
Cd1^i—O3—C9—C9^i	−2.6 (11)	C4—N1—C5—C6	64.1 (8)
Cd1—O4—C9—O3	177.6 (6)	N1—C5—C6—N2	−4.8 (8)
Cd1—O4—C9—C9^i	−2.1 (10)	C2—N2—C6—C5	62.2 (7)
Cd1^ii—O1—C10—O2	−156.2 (6)	C3—N2—C6—C5	−57.1 (7)
Cd1^ii—O1—C10—C10^ii	21.6 (10)	C7—N2—C6—C5	−174.5 (6)
Cd1—O2—C10—O1	−156.4 (6)	C2—N2—C7—C8	58.6 (7)
Cd1—O2—C10—C10^ii	25.7 (9)	C3—N2—C7—C8	179.1 (6)
C5—N1—C1—C2	62.8 (8)	C6—N2—C7—C8	−62.4 (7)
C4—N1—C1—C2	−58.4 (8)	N2—C7—C8—N3	−86 (24)

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···O2^iii	0.83 (8)	1.86 (8)	2.679 (7)	169 (8)
O1W—H1A···O4	0.82	2.45	3.021 (11)	128
O1W—H1A···Cl2	0.82	2.87	3.583 (11)	147
O1W—H1B···Cl1^iv	0.82	2.91	3.701 (12)	162

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