Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536803013576/su6029sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536803013576/su6029Isup2.hkl |
CCDC reference: 217393
Disodium maleonitriledithiolate (Na2mnt) was prepared following the literature procedure (Davison, et al., 1967). 1-(2-Chlorobenzyl)pyridinium chloride was prepared, by reacting 2'-chloro-benzylchlorine with 1.5 equivalents of pyridine in acetone and refluxed for 4 h. The product, a white microcrystalline solid, was filtered off, washed with acetone and diethyl ether in turn. The yield was more than 85% after having been dried in vaccum. NiCl2·6H2O, Na2mnt and 1-(2-chlorobenzyl)pyridinium chloride (equivalent molar ratio 1:2:2) were then combined in water. The precipitate formed was filtered off, washed with water and then dissolved in a little MeCN. Iodine (1 molar equivalent) was added to the solution with stirring at room temperature. Three times the resulting volume of MeOH was then added and the mixture allowed to stand overnight. The microcrystals which formed were filtered off, washed with MeOH and dried in vacuum. Crystals suitable for structure analysis were obtained by diffusing diethyl ether into a MeCN solution of (I).
It was impossible to obtain good quality crystals. This results in a rather high Rint value and the fact that the crystal did not diffract significantly beyond 40° in 2θ.
Data collection: SMART (Siemens, 1996); cell refinement: SMART (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
(C12H11ClN)[Ni(C4N2S2)2] | F(000) = 1100 |
Mr = 543.74 | Dx = 1.595 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 25 reflections |
a = 11.1294 (14) Å | θ = 3.6–15.5° |
b = 6.9653 (9) Å | µ = 1.36 mm−1 |
c = 31.174 (4) Å | T = 293 K |
β = 110.437 (4)° | Needle, black |
V = 2264.5 (5) Å3 | 0.20 × 0.15 × 0.10 mm |
Z = 4 |
Siemens CCD area detector diffractometer | 4443 independent reflections |
Radiation source: fine-focus sealed tube | 2303 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.183 |
ω scans | θmax = 26.1°, θmin = 2.0° |
Absorption correction: empirical (using intensity measurements) (North et al., 1984) | h = −13→9 |
Tmin = 0.770, Tmax = 0.864 | k = −8→8 |
12114 measured reflections | l = −36→38 |
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)] = 0.088 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.199 | H-atom parameters constrained |
S = 1.09 | w = 1/[σ2(Fo2) + (0.0511P)2] where P = (Fo2 + 2Fc2)/3 |
4443 reflections | (Δ/σ)max = 0.017 |
280 parameters | Δρmax = 0.72 e Å−3 |
0 restraints | Δρmin = −0.66 e Å−3 |
(C12H11ClN)[Ni(C4N2S2)2] | V = 2264.5 (5) Å3 |
Mr = 543.74 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 11.1294 (14) Å | µ = 1.36 mm−1 |
b = 6.9653 (9) Å | T = 293 K |
c = 31.174 (4) Å | 0.20 × 0.15 × 0.10 mm |
β = 110.437 (4)° |
Siemens CCD area detector diffractometer | 4443 independent reflections |
Absorption correction: empirical (using intensity measurements) (North et al., 1984) | 2303 reflections with I > 2σ(I) |
Tmin = 0.770, Tmax = 0.864 | Rint = 0.183 |
12114 measured reflections |
R[F2 > 2σ(F2)] = 0.088 | 0 restraints |
wR(F2) = 0.199 | H-atom parameters constrained |
S = 1.09 | Δρmax = 0.72 e Å−3 |
4443 reflections | Δρmin = −0.66 e Å−3 |
280 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 | ||
Ni1 | 0.49071 (7) | 0.92787 (11) | 0.78315 (2) | 0.0551 (3) | |
S1 | 0.43290 (16) | 0.9114 (3) | 0.84206 (5) | 0.0694 (5) | |
S2 | 0.29260 (15) | 0.9349 (3) | 0.73990 (5) | 0.0686 (5) | |
S3 | 0.55471 (16) | 0.9265 (2) | 0.72602 (5) | 0.0626 (4) | |
S4 | 0.68955 (15) | 0.9344 (3) | 0.82425 (5) | 0.0670 (5) | |
N1 | 0.5737 (7) | 0.8848 (12) | 0.9681 (2) | 0.127 (3) | |
N2 | 0.9099 (9) | 0.9361 (14) | 0.9443 (2) | 0.155 (4) | |
N3 | 0.0927 (8) | 0.9390 (11) | 0.6171 (2) | 0.122 (3) | |
N4 | 0.4327 (6) | 0.9152 (9) | 0.60028 (18) | 0.0888 (18) | |
N5 | 0.7362 (6) | 0.8436 (11) | 0.55657 (18) | 0.0840 (18) | |
C1 | 0.5750 (7) | 0.8979 (11) | 0.9320 (2) | 0.090 (2) | |
C2 | 0.5758 (7) | 0.9138 (9) | 0.88617 (19) | 0.0668 (17) | |
C3 | 0.6884 (7) | 0.9220 (9) | 0.8791 (2) | 0.077 (2) | |
C4 | 0.8128 (9) | 0.9296 (12) | 0.9152 (2) | 0.098 (3) | |
C5 | 0.1822 (7) | 0.9368 (11) | 0.6480 (2) | 0.081 (2) | |
C6 | 0.2980 (6) | 0.9321 (9) | 0.68601 (19) | 0.0651 (17) | |
C7 | 0.4162 (7) | 0.9292 (8) | 0.6805 (2) | 0.0612 (16) | |
C8 | 0.4246 (7) | 0.9202 (9) | 0.6360 (2) | 0.0680 (18) | |
C9 | 0.8274 (7) | 0.8036 (17) | 0.5391 (3) | 0.117 (3) | |
H9A | 0.8742 | 0.6902 | 0.5466 | 0.141* | |
C10 | 0.8501 (11) | 0.933 (3) | 0.5100 (3) | 0.150 (6) | |
H10A | 0.9115 | 0.9068 | 0.4968 | 0.180* | |
C11 | 0.7827 (14) | 1.102 (2) | 0.5002 (4) | 0.155 (6) | |
H11A | 0.8023 | 1.1923 | 0.4818 | 0.186* | |
C12 | 0.6855 (11) | 1.1388 (16) | 0.5174 (3) | 0.130 (4) | |
H12A | 0.6359 | 1.2496 | 0.5099 | 0.156* | |
C13 | 0.6675 (10) | 1.0012 (15) | 0.5462 (3) | 0.102 (3) | |
H13A | 0.6040 | 1.0206 | 0.5587 | 0.122* | |
C14 | 0.7046 (6) | 0.6963 (11) | 0.5862 (2) | 0.083 (2) | |
H14A | 0.6390 | 0.7472 | 0.5969 | 0.099* | |
H14B | 0.6702 | 0.5828 | 0.5680 | 0.099* | |
C15 | 0.8185 (6) | 0.6417 (12) | 0.6262 (2) | 0.0707 (18) | |
C16 | 0.8674 (7) | 0.7597 (11) | 0.6640 (2) | 0.080 (2) | |
C17 | 0.9709 (7) | 0.7081 (15) | 0.7006 (2) | 0.092 (2) | |
H17A | 1.0023 | 0.7910 | 0.7254 | 0.111* | |
C18 | 1.0284 (8) | 0.5376 (17) | 0.7012 (3) | 0.102 (3) | |
H18A | 1.1000 | 0.5048 | 0.7264 | 0.122* | |
C19 | 0.9834 (9) | 0.4119 (14) | 0.6655 (4) | 0.113 (3) | |
H19A | 1.0214 | 0.2923 | 0.6664 | 0.135* | |
C20 | 0.8801 (9) | 0.4675 (14) | 0.6280 (3) | 0.101 (3) | |
H20A | 0.8506 | 0.3851 | 0.6030 | 0.121* | |
Cl1 | 0.7937 (2) | 0.9798 (3) | 0.66419 (6) | 0.1007 (7) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ni1 | 0.0585 (5) | 0.0587 (5) | 0.0465 (4) | −0.0016 (4) | 0.0164 (3) | −0.0026 (3) |
S1 | 0.0694 (10) | 0.0883 (13) | 0.0528 (9) | 0.0114 (9) | 0.0241 (8) | 0.0000 (8) |
S2 | 0.0548 (9) | 0.0906 (13) | 0.0569 (9) | −0.0054 (9) | 0.0150 (7) | −0.0009 (8) |
S3 | 0.0636 (9) | 0.0733 (11) | 0.0507 (8) | −0.0042 (8) | 0.0196 (7) | −0.0019 (8) |
S4 | 0.0583 (9) | 0.0845 (13) | 0.0524 (9) | −0.0006 (8) | 0.0121 (7) | −0.0042 (8) |
N1 | 0.128 (6) | 0.203 (8) | 0.051 (4) | 0.064 (6) | 0.034 (4) | 0.015 (4) |
N2 | 0.132 (7) | 0.238 (11) | 0.062 (4) | 0.004 (7) | −0.007 (5) | −0.026 (5) |
N3 | 0.097 (5) | 0.160 (8) | 0.077 (4) | −0.024 (5) | −0.009 (4) | 0.007 (4) |
N4 | 0.114 (5) | 0.098 (5) | 0.048 (3) | −0.011 (4) | 0.021 (3) | −0.003 (3) |
N5 | 0.070 (4) | 0.115 (6) | 0.055 (3) | −0.037 (4) | 0.007 (3) | −0.011 (4) |
C1 | 0.089 (5) | 0.116 (7) | 0.062 (5) | 0.050 (5) | 0.023 (4) | 0.006 (4) |
C2 | 0.077 (4) | 0.074 (5) | 0.049 (3) | 0.020 (4) | 0.021 (3) | −0.005 (3) |
C3 | 0.084 (5) | 0.081 (5) | 0.051 (4) | 0.012 (4) | 0.004 (3) | −0.013 (3) |
C4 | 0.106 (6) | 0.118 (7) | 0.053 (4) | 0.020 (5) | 0.008 (4) | −0.015 (4) |
C5 | 0.072 (4) | 0.101 (6) | 0.054 (4) | −0.016 (4) | 0.002 (4) | 0.007 (4) |
C6 | 0.071 (4) | 0.066 (4) | 0.049 (3) | −0.014 (3) | 0.008 (3) | −0.004 (3) |
C7 | 0.083 (4) | 0.048 (4) | 0.052 (3) | −0.013 (3) | 0.024 (3) | 0.002 (3) |
C8 | 0.089 (5) | 0.060 (4) | 0.048 (4) | −0.014 (4) | 0.016 (3) | −0.006 (3) |
C9 | 0.077 (5) | 0.192 (10) | 0.087 (5) | −0.030 (6) | 0.033 (5) | 0.004 (6) |
C10 | 0.094 (7) | 0.285 (18) | 0.070 (6) | −0.073 (9) | 0.028 (5) | 0.001 (8) |
C11 | 0.132 (10) | 0.228 (16) | 0.077 (7) | −0.062 (10) | 0.001 (7) | 0.045 (8) |
C12 | 0.154 (9) | 0.158 (9) | 0.052 (5) | −0.055 (8) | 0.004 (5) | 0.005 (5) |
C13 | 0.114 (7) | 0.125 (8) | 0.063 (5) | −0.041 (6) | 0.026 (5) | −0.016 (5) |
C14 | 0.079 (5) | 0.101 (6) | 0.067 (4) | −0.042 (4) | 0.024 (4) | −0.011 (4) |
C15 | 0.059 (4) | 0.089 (5) | 0.069 (4) | −0.017 (4) | 0.028 (3) | −0.005 (4) |
C16 | 0.073 (4) | 0.100 (6) | 0.074 (5) | −0.019 (4) | 0.037 (4) | −0.008 (4) |
C17 | 0.077 (5) | 0.133 (8) | 0.061 (4) | −0.002 (5) | 0.017 (4) | 0.004 (5) |
C18 | 0.066 (5) | 0.147 (9) | 0.085 (6) | −0.006 (6) | 0.018 (4) | 0.027 (6) |
C19 | 0.080 (6) | 0.116 (8) | 0.149 (9) | −0.012 (6) | 0.049 (6) | 0.006 (7) |
C20 | 0.087 (6) | 0.116 (8) | 0.099 (6) | −0.032 (6) | 0.032 (5) | −0.029 (5) |
Cl1 | 0.1131 (15) | 0.1066 (16) | 0.0794 (12) | −0.0027 (13) | 0.0298 (11) | −0.0174 (11) |
Ni1—S3 | 2.1367 (16) | C9—H9A | 0.9300 |
Ni1—S4 | 2.1356 (17) | C10—C11 | 1.369 (16) |
Ni1—S2 | 2.1460 (17) | C10—H10A | 0.9300 |
Ni1—S1 | 2.1505 (16) | C11—C12 | 1.388 (16) |
S1—C2 | 1.701 (7) | C11—H11A | 0.9300 |
S2—C6 | 1.702 (6) | C12—C13 | 1.374 (11) |
S3—C7 | 1.691 (7) | C12—H12A | 0.9300 |
S4—C3 | 1.716 (7) | C13—H13A | 0.9300 |
N1—C1 | 1.134 (8) | C14—C15 | 1.485 (9) |
N2—C4 | 1.144 (10) | C14—H14A | 0.9700 |
N3—C5 | 1.117 (8) | C14—H14B | 0.9700 |
N4—C8 | 1.147 (7) | C15—C20 | 1.385 (11) |
N5—C13 | 1.313 (11) | C15—C16 | 1.383 (9) |
N5—C9 | 1.337 (9) | C16—C17 | 1.357 (9) |
N5—C14 | 1.502 (8) | C16—Cl1 | 1.740 (8) |
C1—C2 | 1.437 (9) | C17—C18 | 1.346 (11) |
C2—C3 | 1.349 (9) | C17—H17A | 0.9300 |
C3—C4 | 1.448 (10) | C18—C19 | 1.368 (12) |
C5—C6 | 1.414 (9) | C18—H18A | 0.9300 |
C6—C7 | 1.385 (9) | C19—C20 | 1.378 (12) |
C7—C8 | 1.426 (8) | C19—H19A | 0.9300 |
C9—C10 | 1.364 (14) | C20—H20A | 0.9300 |
S3—Ni1—S4 | 85.58 (6) | C11—C10—H10A | 120.0 |
S3—Ni1—S2 | 92.57 (6) | C10—C11—C12 | 120.9 (12) |
S4—Ni1—S2 | 176.87 (7) | C10—C11—H11A | 119.5 |
S3—Ni1—S1 | 176.18 (7) | C12—C11—H11A | 119.5 |
S4—Ni1—S1 | 92.59 (7) | C13—C12—C11 | 115.6 (12) |
S2—Ni1—S1 | 89.41 (7) | C13—C12—H12A | 122.2 |
C2—S1—Ni1 | 102.5 (2) | C11—C12—H12A | 122.2 |
C6—S2—Ni1 | 103.7 (2) | N5—C13—C12 | 122.6 (10) |
C7—S3—Ni1 | 103.2 (2) | N5—C13—H13A | 118.7 |
C3—S4—Ni1 | 103.3 (3) | C12—C13—H13A | 118.7 |
C13—N5—C9 | 122.3 (8) | C15—C14—N5 | 112.1 (5) |
C13—N5—C14 | 118.8 (7) | C15—C14—H14A | 109.2 |
C9—N5—C14 | 118.8 (8) | N5—C14—H14A | 109.2 |
N1—C1—C2 | 179.6 (10) | C15—C14—H14B | 109.2 |
C3—C2—C1 | 119.7 (6) | N5—C14—H14B | 109.2 |
C3—C2—S1 | 121.9 (5) | H14A—C14—H14B | 107.9 |
C1—C2—S1 | 118.4 (5) | C20—C15—C16 | 116.4 (7) |
C2—C3—C4 | 124.4 (6) | C20—C15—C14 | 121.5 (7) |
C2—C3—S4 | 119.7 (5) | C16—C15—C14 | 122.0 (7) |
C4—C3—S4 | 115.8 (6) | C17—C16—C15 | 121.7 (8) |
N2—C4—C3 | 178.7 (9) | C17—C16—Cl1 | 119.6 (6) |
N3—C5—C6 | 178.1 (9) | C15—C16—Cl1 | 118.8 (6) |
C7—C6—C5 | 121.5 (6) | C16—C17—C18 | 120.4 (8) |
C7—C6—S2 | 119.0 (5) | C16—C17—H17A | 119.8 |
C5—C6—S2 | 119.4 (5) | C18—C17—H17A | 119.8 |
C6—C7—C8 | 120.6 (6) | C17—C18—C19 | 121.1 (8) |
C6—C7—S3 | 121.5 (5) | C17—C18—H18A | 119.4 |
C8—C7—S3 | 117.8 (5) | C19—C18—H18A | 119.5 |
N4—C8—C7 | 178.9 (7) | C18—C19—C20 | 118.1 (9) |
N5—C9—C10 | 118.4 (11) | C18—C19—H19A | 121.0 |
N5—C9—H9A | 120.8 | C20—C19—H19A | 121.0 |
C10—C9—H9A | 120.8 | C15—C20—C19 | 122.3 (8) |
C9—C10—C11 | 120.1 (12) | C15—C20—H20A | 118.8 |
C9—C10—H10A | 120.0 | C19—C20—H20A | 118.9 |
Experimental details
Crystal data | |
Chemical formula | (C12H11ClN)[Ni(C4N2S2)2] |
Mr | 543.74 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 11.1294 (14), 6.9653 (9), 31.174 (4) |
β (°) | 110.437 (4) |
V (Å3) | 2264.5 (5) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.36 |
Crystal size (mm) | 0.20 × 0.15 × 0.10 |
Data collection | |
Diffractometer | Siemens CCD area detector diffractometer |
Absorption correction | Empirical (using intensity measurements) (North et al., 1984) |
Tmin, Tmax | 0.770, 0.864 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 12114, 4443, 2303 |
Rint | 0.183 |
(sin θ/λ)max (Å−1) | 0.618 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.088, 0.199, 1.09 |
No. of reflections | 4443 |
No. of parameters | 280 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.72, −0.66 |
Computer programs: SMART (Siemens, 1996), SAINT, SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), SHELXTL.
Ni1—S3 | 2.1367 (16) | Ni1—S2 | 2.1460 (17) |
Ni1—S4 | 2.1356 (17) | Ni1—S1 | 2.1505 (16) |
S3—Ni1—S4 | 85.58 (6) | S3—Ni1—S1 | 176.18 (7) |
S3—Ni1—S2 | 92.57 (6) | S4—Ni1—S1 | 92.59 (7) |
S4—Ni1—S2 | 176.87 (7) | S2—Ni1—S1 | 89.41 (7) |
In recent years many new effects have been found especially for low-dimensional spin systems (Caneschi et al., 2001; Wolf et al., 2002; Mitsumi et al., 2002; Lorenz et al., 2002). Our aim is to construct quasi-one-dimensional molecule-based magnetic materials formed by plate-like maleonitriledithiolene (mnt) anionic metal complexes [M(mnt)2]− (M is Ni3+, Pd3+ or Pt3+). The magnetic properties of these types of low-dimensional magnetic materials are associated with columnar crystallographic packing. Recently, we have developed a new class of [R-BzPy]+[Ni(mnt)2]− salts, using the [Ni(mnt)2]− anion and derivatives of benzylpyridinium ([R-BzPy]+) as building blocks to construct low-dimensional molecular solids. We have found that the topology and size of the [R-BzPy]+ ion, which is related to its molecular conformation, can be modulated by systematic variation of the substituents on the aromatic rings. Hence, the stacking pattern of these complexes can be finely tuned through controlling the molecular conformation of the [R–BzPy]+ ion. To test this idea, a series of complexes have been obtained, which exhibit magnetic diversity (Ren et al., 2002; Xie, Ren, Song, Zou & Meng, 2002; Xie, Ren, Song, Zhang et al., 2002; Xie et al., 2003). In order to obtain further information concerning the nature of the effects of the substituents on the stacking pattern of these classes of ion-pair complexes, we report here the crystal structure of the title compound, (I), which has columnar packing.
In the anion of (I), the Ni atom exhibits square-planar coordination geometry involving four S atoms. The five-membered nickel-containing rings are slightly puckered (Fig. 1), as has been found in other [M(mnt)2]n- structures (Plumlee et al., 1975). The average S—Ni—S bond angle within the five-membered ring is 92.58 (6)° and the average Ni—S bond distance is 2.142 (2) Å. This compares well with similar bond distances and angles found in [Ni(mnt)2]− complexes (Ren et al., 2001, 2002). The anion is nearly planar, however the CN groups bend somewhat away from the plane of the four S atoms. For example, the largest deviations from the plane defined by the four S atoms are 0.149 (6) and 0.212 (6) Å for atoms C8 and N4, respectively.
The cation adopts a Λ-shape conformation, similar to other complexes in these series. However, the dihedral angles between the aromic rings and the reference plane deviate considerabley from 90°. The pyridine ring and the C14/C15/N5 reference plane are inclined by 55.06 (44)°, and the benzene ring is twisted towards the reference plane with a dihedral angle of 75.04 (53)°. This is different from the case of 1-(4-X-benzyl)pyridinium derivatives (X = substitutent).
The most prominent structural features of complex (I) are the completely segregated stacking columns of the [Ni(mnt)2]− anions and 1-(2-chlorobenzyl)pyridinium cations. This is illustrated by the projection along the crystallographic b axis shown in Fig. 2. Reports of completely segregated stacked columns of [Ni(mnt)2]− anions are rare (Ren et al., 2001). The Ni1···Ni1i [symmetry code: (i) 1 − x, −1/2 + y, 3/2 − z] distances between neighbouring anions within the [Ni(mnt)2]− column are equal [4.0917 (8) Å]. Hence, the Ni3+ ions form a uniformly spaced magnetic chain along the direction of the anionic column (Fig. 3). In the magnetic chain the shortest S···S (S2···S3i) and Ni···S (Ni1···S3i) distances are 3.806 (2) and 3.507 (2) Å, respectively. The nearest Ni1···Ni1ii [symmetry code: (ii) −x, −1/2 + y, 3/2 − z] contact between the [Ni(mnt)2]− columns is 10.952 (2) Å, which is much longer than the Ni···Ni distance within the [Ni(mnt)2]− column. These results indicate that, compared with intracolumnar interactions, the Ni···Ni magnetic exchange interactions between columns may be neglected, so this complex is an ideal magnetic chain compound. Within the column of 1-(2-chlorobenzyl)pyridinium cations, no π–π- or Cl–π-stacking interactions are found, which exist in 1-(4-chlorobenzyl)pyridinium bis(maleonitriledithiolato)nickelate(III) (Ren et al., 2002).