Tetra-n-butyl­ammonium bis­(1,2-dimercaptoethene-1,2-dicarbo­nitrilato-S,S')­nickel(III)

The crystal structure of the title compound, (C₁₆H₃₆N)[Ni(C₄N₂S₂)₂], shows stacking of the dimerized anions, surrounded by columns of cations.

S1. Comment

1,3-Dithiolato complexes of transition metals are planar electronic acceptors, which have received attention in connection with their magnetic and electrical conducting properties. The discovery of a ferromagnetic ordering in (NH₄)[Ni(mnt)₂]-H₂O below 4.5 K (Coomber et al., 1996) has especially stimulated interest in M(mnt)₂-based compounds (mnt = S₂C₄N₂²⁻ = dimercaptomaleodinitrilato-). Structures for several tetraalkylammonium salts of the Ni(mnt)₂ anions have been reported so far, most of which are Ni^II salts represented as (R₄N)₂[Ni(mnt)₂], where R = Me (Eisenberg & Ibers, 1965), Et (Mahadevan et al., 1984) and n-Bu (Kobayashi & Sasaki, 1977), while (Et₄N)[Ni(mnt)₂] is the only example of an Ni^III salt (Kobayashi & Sasaki, 1977). \sch

Fig. 1 presents an ORTEP (Spek, 2000) diagram and Fig. 2 a packing diagram of [(n-C₄H₉)₄N][Ni(mnt)₂], (I). The intramolecular Ni—S and S—C distances (Table 1) in the anion are quite consistent with the corresponding values in [Ni(mnt)₂]⁻ (Mahadevan et al., 1984). The anions form dimers and are stacked in columnar fashion along the c axis. Important intermolecular distances between the anions are listed in Table 2. Within the dimer, the long molecular axes of the anions are parallel, being in a slipped configuration such that the central metal atoms are positioned above the S atom of the other anion with a Ni···S distance of 3.7148 (9) Å. This stacking mode is often observed in [Ni(mnt)₂]ⁿ⁻ salts. The Ni···Ni distance within the dimer is 3.9963 (8) Å. The long axis of an adjacent molecule is making an angle of ca 65° with that in the dimer, interacting via a Ni···S contact of 3.715 (1) Å. The intradimer Ni···Ni distance is 4.5263 (8) Å. Measurements of electrical conductivity revealed that the material is an insulator, which is consistent with the acceptor arrangement as shown above. The anion stack is surrounded by columns of cations. The n-Bu groups in the cation have an all-trans conformation.

We finally note that a report was found on a corresponding Au^III complex, [(n-Bu)₄N][Au(mnt)₂] (Saluschke et al., 1996) in the CCDC database. Although no coordinates are given, it is highly probable that the complex is isomorphous with the present compound, judging from the similarity in space group and cell parameters (C2/c, a = 30.853, b = 13.923, c = 15.759, β = 115.78).

S2. Experimental

The title compound was purchased from Tokyo Kasei Kogyo Co., Ltd. Single crystals were grown by vapour diffusion of ether into acetonitrile solutions of the compound.

S3. Refinement

H atoms were fixed at ideal positions with B_iso values of 6.0 Å.

Computing details

Data collection: MSC/AFC Diffractometer Control Software (MSC, 1999); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN (Molecular Structure Corporation, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: TEXSAN; software used to prepare material for publication: TEXSAN.

Figures

	Fig. 1. ORTEP (Spek, 2000) drawing of (I). The displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. Packing diagram of (I). H atoms are omitted for clarity.

(I)

Crystal data

(C16H36N)[Ni(C4N2S2)2]	Dx = 1.284 Mg m^−3 Dm = 1.286 Mg m^−3 Dm measured by flotation
Mr = 581.52	Mo Kα radiation, λ = 0.7107 Å
Monoclinic, C2/c	Cell parameters from 24 reflections
a = 30.879 (6) Å	θ = 14.9–15.0°
b = 13.793 (5) Å	µ = 0.94 mm^−1
c = 15.669 (5) Å	T = 296 K
β = 115.68 (2)°	Prismatic, black
V = 6014 (3) Å^3	0.38 × 0.30 × 0.18 mm
Z = 8

Data collection

Rigaku AFC7R diffractometer	Rint = 0.015
ω–2θ scans	θmax = 27.5°
Absorption correction: analytical Tompa analytical	h = 0→40
Tmin = 0.704, Tmax = 0.809	k = 0→17
7332 measured reflections	l = −20→18
6914 independent reflections	3 standard reflections every 150 reflections
4451 reflections with F^2 > 2.0σ(F^2)	intensity decay: 0.8%

Refinement

Refinement on F^2	H-atom parameters not refined
R[F^2 > 2σ(F^2)] = 0.041	w = 1/(σ^2(Fo^2) + {0.05[Max(Fo^2,0) + 2Fc^2]/3}^2)
wR(F^2) = 0.105	(Δ/σ)max = 0.020
S = 1.28	Δρmax = 0.39 e Å^−3
4451 reflections	Δρmin = −0.35 e Å^−3
307 parameters

Special details

Refinement. Refinement using reflections with F² > 2.0 σ(F²). The weighted R-factor (wR) and goodness of fit (S) are based on F². R-factor (gt) are based on F. The threshold expression of F² > 2.0 σ(F²) is used only for calculating R-factor (gt).

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

	x	y	z	Uiso*/Ueq
Ni	0.01800 (1)	0.56307 (3)	0.40622 (2)	0.05591 (9)
S(1)	0.00481 (3)	0.71637 (6)	0.39248 (6)	0.0726 (2)
S(2)	−0.05116 (3)	0.53147 (6)	0.29341 (5)	0.0632 (2)
S(3)	0.08606 (3)	0.59598 (6)	0.52105 (6)	0.0715 (2)
S(4)	0.03267 (3)	0.41049 (6)	0.41894 (5)	0.0654 (2)
N(1)	−0.0877 (1)	0.8971 (2)	0.2570 (2)	0.102 (1)
N(2)	−0.1608 (1)	0.6487 (3)	0.1192 (2)	0.106 (1)
N(3)	0.1952 (1)	0.4780 (3)	0.6983 (2)	0.126 (1)
N(4)	0.1289 (1)	0.2357 (2)	0.5604 (2)	0.108 (1)
N(5)	0.16095 (7)	0.0931 (2)	0.0801 (1)	0.0526 (6)
C(1)	−0.05214 (10)	0.7255 (2)	0.3023 (2)	0.0649 (8)
C(2)	−0.07667 (10)	0.6440 (2)	0.2583 (2)	0.0615 (8)
C(3)	0.11235 (10)	0.4847 (2)	0.5565 (2)	0.0623 (8)
C(4)	0.08897 (10)	0.4033 (2)	0.5109 (2)	0.0589 (7)
C(5)	−0.0723 (1)	0.8206 (3)	0.2760 (2)	0.0775 (10)
C(6)	−0.1234 (1)	0.6478 (3)	0.1805 (2)	0.0750 (10)
C(7)	0.1585 (1)	0.4808 (3)	0.6360 (2)	0.083 (1)
C(8)	0.1106 (1)	0.3094 (2)	0.5390 (2)	0.0746 (9)
C(9)	0.11370 (9)	0.0818 (2)	−0.0071 (2)	0.0622 (8)
C(10)	0.0849 (1)	−0.0077 (3)	−0.0110 (2)	0.0830 (10)
C(11)	0.0386 (1)	−0.0111 (3)	−0.0997 (3)	0.095 (1)
C(12)	0.0087 (1)	−0.0976 (4)	−0.1090 (3)	0.124 (2)
C(13)	0.15358 (10)	0.0963 (2)	0.1701 (2)	0.0590 (7)
C(14)	0.1240 (1)	0.1806 (2)	0.1776 (2)	0.0717 (9)
C(15)	0.1222 (1)	0.1808 (3)	0.2720 (2)	0.091 (1)
C(16)	0.0954 (2)	0.2663 (4)	0.2855 (3)	0.129 (2)
C(17)	0.18274 (9)	0.1870 (2)	0.0663 (2)	0.0574 (7)
C(18)	0.2292 (1)	0.2175 (2)	0.1477 (2)	0.0708 (9)
C(19)	0.2470 (1)	0.3109 (2)	0.1231 (2)	0.082 (1)
C(20)	0.2901 (1)	0.3514 (3)	0.2019 (3)	0.101 (1)
C(21)	0.19403 (9)	0.0074 (2)	0.0915 (2)	0.0596 (7)
C(22)	0.2110 (1)	−0.0065 (3)	0.0164 (3)	0.087 (1)
C(23)	0.2436 (2)	−0.0951 (3)	0.0398 (3)	0.121 (2)
C(24)	0.2709 (2)	−0.1054 (5)	−0.0096 (6)	0.204 (3)
H(1)	0.1381	0.0381	0.1735	0.0711*
H(2)	0.1845	0.0996	0.2225	0.0711*
H(3)	0.1382	0.2395	0.1707	0.0864*
H(4)	0.0924	0.1755	0.1288	0.0864*
H(5)	0.1069	0.1229	0.2773	0.1095*
H(6)	0.1541	0.1825	0.3206	0.1095*
H(7)	0.0943	0.1366	−0.0105	0.0748*
H(8)	0.1204	0.0810	−0.0609	0.0748*
H(9)	0.1035	−0.0632	−0.0090	0.0995*
H(10)	0.0777	−0.0078	0.0420	0.0995*
H(11)	0.0204	0.0444	−0.1009	0.1135*
H(12)	0.0463	−0.0098	−0.1523	0.1135*
H(13)	0.0004	−0.1005	−0.0576	0.1501*
H(14)	−0.0196	−0.0944	−0.1669	0.1501*
H(15)	0.0263	−0.1546	−0.1091	0.1501*
H(16)	0.2216	0.0153	0.1500	0.0725*
H(17)	0.1773	−0.0496	0.0935	0.0725*
H(18)	0.1841	−0.0165	−0.0429	0.1037*
H(19)	0.2280	0.0495	0.0129	0.1037*
H(22)	0.1886	0.1798	0.0120	0.0690*
H(23)	0.1598	0.2372	0.0555	0.0690*
H(24)	0.2238	0.2277	0.2027	0.0850*
H(25)	0.2526	0.1684	0.1604	0.0850*
H(26)	0.2544	0.2985	0.0713	0.0990*
H(27)	0.2218	0.3576	0.1047	0.0990*
H(28)	0.3154	0.3055	0.2211	0.1210*
H(29)	0.2995	0.4092	0.1817	0.1210*
H(30)	0.2828	0.3656	0.2537	0.1210*
H(31)	0.1102	0.3246	0.2802	0.1539*
H(32)	0.0629	0.2652	0.2366	0.1539*
H(33)	0.0948	0.2626	0.3450	0.1539*
H(34)	0.2671	−0.0906	0.1039	0.1443*
H(35)	0.2253	−0.1517	0.0308	0.1443*
H(36)	0.2906	−0.1614	0.0033	0.2039*
H(37)	0.2486	−0.1129	−0.0817	0.2039*
H(38)	0.2898	−0.0498	−0.0097	0.2039*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni	0.0548 (2)	0.0523 (2)	0.0603 (2)	−0.0039 (2)	0.0247 (1)	−0.0041 (2)
S(1)	0.0673 (4)	0.0534 (4)	0.0859 (5)	−0.0037 (3)	0.0228 (4)	−0.0018 (4)
S(2)	0.0595 (4)	0.0611 (4)	0.0655 (4)	−0.0027 (3)	0.0236 (3)	−0.0084 (3)
S(3)	0.0686 (4)	0.0558 (4)	0.0757 (5)	−0.0124 (3)	0.0177 (4)	−0.0063 (4)
S(4)	0.0629 (4)	0.0544 (4)	0.0673 (4)	−0.0035 (3)	0.0175 (3)	−0.0091 (3)
N(1)	0.094 (2)	0.069 (2)	0.138 (3)	0.012 (2)	0.046 (2)	0.024 (2)
N(2)	0.079 (2)	0.127 (3)	0.086 (2)	0.010 (2)	0.012 (2)	−0.001 (2)
N(3)	0.090 (2)	0.120 (3)	0.109 (2)	−0.019 (2)	−0.012 (2)	0.021 (2)
N(4)	0.113 (2)	0.070 (2)	0.109 (2)	0.018 (2)	0.016 (2)	0.005 (2)
N(5)	0.048 (1)	0.048 (1)	0.053 (1)	0.0025 (9)	0.0141 (9)	0.0064 (9)
C(1)	0.067 (2)	0.062 (2)	0.071 (2)	0.003 (1)	0.035 (1)	0.007 (1)
C(2)	0.063 (1)	0.069 (2)	0.059 (1)	0.001 (1)	0.032 (1)	0.002 (1)
C(3)	0.062 (2)	0.064 (2)	0.056 (1)	−0.006 (1)	0.021 (1)	0.001 (1)
C(4)	0.062 (1)	0.060 (2)	0.056 (1)	−0.001 (1)	0.027 (1)	0.002 (1)
C(5)	0.074 (2)	0.070 (2)	0.088 (2)	0.001 (2)	0.036 (2)	0.005 (2)
C(6)	0.073 (2)	0.083 (2)	0.069 (2)	0.006 (2)	0.031 (1)	0.002 (2)
C(7)	0.077 (2)	0.077 (2)	0.076 (2)	−0.012 (2)	0.016 (2)	0.008 (2)
C(8)	0.076 (2)	0.068 (2)	0.068 (2)	−0.002 (2)	0.020 (1)	−0.004 (2)
C(9)	0.050 (1)	0.061 (2)	0.059 (2)	0.005 (1)	0.009 (1)	0.010 (1)
C(10)	0.060 (2)	0.072 (2)	0.092 (2)	−0.006 (2)	0.010 (2)	0.009 (2)
C(11)	0.068 (2)	0.103 (3)	0.091 (2)	−0.013 (2)	0.014 (2)	0.001 (2)
C(12)	0.081 (2)	0.132 (4)	0.132 (4)	−0.033 (2)	0.020 (2)	−0.003 (3)
C(13)	0.059 (1)	0.055 (2)	0.056 (1)	0.002 (1)	0.019 (1)	0.011 (1)
C(14)	0.076 (2)	0.066 (2)	0.077 (2)	0.009 (1)	0.037 (1)	0.011 (2)
C(15)	0.109 (2)	0.090 (2)	0.078 (2)	0.010 (2)	0.046 (2)	0.001 (2)
C(16)	0.161 (4)	0.120 (4)	0.128 (3)	0.028 (3)	0.084 (3)	−0.015 (3)
C(17)	0.058 (1)	0.048 (1)	0.064 (1)	0.001 (1)	0.024 (1)	0.005 (1)
C(18)	0.063 (2)	0.065 (2)	0.075 (2)	−0.008 (1)	0.021 (1)	−0.001 (1)
C(19)	0.091 (2)	0.069 (2)	0.078 (2)	−0.018 (2)	0.029 (2)	−0.011 (2)
C(20)	0.091 (2)	0.090 (3)	0.103 (3)	−0.024 (2)	0.025 (2)	−0.023 (2)
C(21)	0.050 (1)	0.050 (1)	0.068 (2)	0.005 (1)	0.015 (1)	0.003 (1)
C(22)	0.093 (2)	0.067 (2)	0.111 (2)	0.011 (2)	0.053 (2)	0.000 (2)
C(23)	0.137 (3)	0.078 (3)	0.192 (4)	0.019 (2)	0.111 (2)	−0.001 (3)
C(24)	0.186 (5)	0.111 (4)	0.373 (8)	0.026 (4)	0.177 (5)	0.005 (5)

Geometric parameters (Å, º)

Ni—S(1)	2.1465 (9)	C(1)—C(5)	1.433 (5)
Ni—S(2)	2.1458 (9)	C(2)—C(6)	1.431 (5)
Ni—S(3)	2.1409 (9)	C(3)—C(4)	1.358 (4)
Ni—S(4)	2.1437 (9)	C(3)—C(7)	1.431 (5)
S(1)—C(1)	1.718 (3)	C(4)—C(8)	1.437 (5)
S(2)—C(2)	1.719 (3)	C(9)—C(10)	1.506 (5)
S(3)—C(3)	1.712 (3)	C(10)—C(11)	1.503 (5)
S(4)—C(4)	1.714 (3)	C(11)—C(12)	1.476 (6)
N(1)—C(5)	1.142 (5)	C(13)—C(14)	1.514 (4)
N(2)—C(6)	1.137 (4)	C(14)—C(15)	1.505 (5)
N(3)—C(7)	1.131 (5)	C(15)—C(16)	1.507 (6)
N(4)—C(8)	1.139 (5)	C(17)—C(18)	1.508 (4)
N(5)—C(9)	1.514 (4)	C(18)—C(19)	1.513 (5)
N(5)—C(13)	1.523 (4)	C(19)—C(20)	1.479 (5)
N(5)—C(17)	1.518 (4)	C(21)—C(22)	1.495 (5)
N(5)—C(21)	1.521 (4)	C(22)—C(23)	1.522 (6)
C(1)—C(2)	1.365 (4)	C(23)—C(24)	1.377 (7)
Ni···S(2)^i	3.7148 (9)	Ni···Ni^i	4.5263 (8)
Ni···S(4)^ii	3.715 (1)	Ni···Ni^ii	3.9963 (8)
S(1)—Ni—S(2)	92.27 (4)	S(3)—C(3)—C(4)	120.1 (2)
S(1)—Ni—S(3)	87.13 (4)	S(3)—C(3)—C(7)	118.0 (3)
S(1)—Ni—S(4)	178.52 (4)	C(4)—C(3)—C(7)	121.9 (3)
S(2)—Ni—S(3)	178.44 (4)	S(4)—C(4)—C(3)	120.6 (3)
S(2)—Ni—S(4)	88.40 (4)	S(4)—C(4)—C(8)	118.5 (2)
S(3)—Ni—S(4)	92.24 (4)	C(3)—C(4)—C(8)	120.9 (3)
Ni—S(1)—C(1)	103.7 (1)	N(1)—C(5)—C(1)	178.5 (4)
Ni—S(2)—C(2)	103.6 (1)	N(2)—C(6)—C(2)	178.3 (4)
Ni—S(3)—C(3)	103.7 (1)	N(3)—C(7)—C(3)	179.3 (5)
Ni—S(4)—C(4)	103.4 (1)	N(4)—C(8)—C(4)	177.9 (4)
C(9)—N(5)—C(13)	111.5 (2)	N(5)—C(9)—C(10)	116.2 (2)
C(9)—N(5)—C(17)	105.8 (2)	C(9)—C(10)—C(11)	111.9 (3)
C(9)—N(5)—C(21)	111.2 (2)	C(10)—C(11)—C(12)	114.9 (4)
C(13)—N(5)—C(17)	111.1 (2)	N(5)—C(13)—C(14)	115.6 (2)
C(13)—N(5)—C(21)	106.0 (2)	C(13)—C(14)—C(15)	111.0 (3)
C(17)—N(5)—C(21)	111.3 (2)	C(14)—C(15)—C(16)	113.3 (4)
S(1)—C(1)—C(2)	120.1 (3)	N(5)—C(17)—C(18)	115.8 (2)
S(1)—C(1)—C(5)	117.8 (3)	C(17)—C(18)—C(19)	109.8 (3)
C(2)—C(1)—C(5)	122.1 (3)	C(18)—C(19)—C(20)	113.8 (3)
S(2)—C(2)—C(1)	120.3 (3)	N(5)—C(21)—C(22)	117.0 (3)
S(2)—C(2)—C(6)	117.4 (3)	C(21)—C(22)—C(23)	109.5 (4)
C(1)—C(2)—C(6)	122.3 (3)	C(22)—C(23)—C(24)	116.7 (5)
Ni—S(1)—C(1)—C(2)	−0.8 (3)	S(4)—C(4)—C(3)—C(7)	177.4 (3)
Ni—S(1)—C(1)—C(5)	179.1 (2)	S(4)—C(4)—C(8)—N(4)	114 (10)
Ni—S(2)—C(2)—C(1)	−0.2 (3)	N(1)—C(5)—C(1)—C(2)	158 (15)
Ni—S(2)—C(2)—C(6)	178.1 (2)	N(2)—C(6)—C(2)—C(1)	−154 (13)
Ni—S(3)—C(3)—C(4)	0.8 (3)	N(3)—C(7)—C(3)—C(4)	108 (38)
Ni—S(3)—C(3)—C(7)	−177.7 (3)	N(4)—C(8)—C(4)—C(3)	−65 (11)
Ni—S(4)—C(4)—C(3)	0.7 (3)	N(5)—C(9)—C(10)—C(11)	179.3 (3)
Ni—S(4)—C(4)—C(8)	−179.6 (2)	N(5)—C(13)—C(14)—C(15)	−175.8 (3)
S(1)—Ni—S(2)—C(2)	−0.2 (1)	N(5)—C(17)—C(18)—C(19)	178.9 (3)
S(1)—Ni—S(3)—C(3)	−178.9 (1)	N(5)—C(21)—C(22)—C(23)	179.9 (3)
S(1)—Ni—S(4)—C(4)	64 (1)	C(5)—C(1)—C(2)—C(6)	2.5 (5)
S(1)—C(1)—C(2)—S(2)	0.7 (4)	C(7)—C(3)—C(4)—C(8)	−2.2 (5)
S(1)—C(1)—C(2)—C(6)	−177.6 (2)	C(9)—N(5)—C(13)—C(14)	−62.6 (3)
S(1)—C(1)—C(5)—N(1)	−21 (15)	C(9)—N(5)—C(17)—C(18)	176.4 (3)
S(2)—Ni—S(1)—C(1)	0.5 (1)	C(9)—N(5)—C(21)—C(22)	64.5 (3)
S(2)—Ni—S(3)—C(3)	113 (1)	C(9)—C(10)—C(11)—C(12)	179.3 (4)
S(2)—Ni—S(4)—C(4)	−178.8 (1)	C(10)—C(9)—N(5)—C(13)	−59.6 (4)
S(2)—C(2)—C(1)—C(5)	−179.2 (3)	C(10)—C(9)—N(5)—C(17)	179.5 (3)
S(2)—C(2)—C(6)—N(2)	27 (13)	C(10)—C(9)—N(5)—C(21)	58.4 (4)
S(3)—Ni—S(1)—C(1)	−178.1 (1)	C(13)—N(5)—C(17)—C(18)	55.3 (3)
S(3)—Ni—S(2)—C(2)	67 (1)	C(13)—N(5)—C(21)—C(22)	−174.2 (3)
S(3)—Ni—S(4)—C(4)	−0.2 (1)	C(13)—C(14)—C(15)—C(16)	176.9 (4)
S(3)—C(3)—C(4)—S(4)	−1.1 (4)	C(14)—C(13)—N(5)—C(17)	55.2 (3)
S(3)—C(3)—C(4)—C(8)	179.3 (3)	C(14)—C(13)—N(5)—C(21)	176.2 (3)
S(3)—C(3)—C(7)—N(3)	−73 (38)	C(17)—N(5)—C(21)—C(22)	−53.3 (3)
S(4)—Ni—S(1)—C(1)	117 (1)	C(17)—C(18)—C(19)—C(20)	174.8 (3)
S(4)—Ni—S(2)—C(2)	−178.9 (1)	C(18)—C(17)—N(5)—C(21)	−62.6 (3)
S(4)—Ni—S(3)—C(3)	−0.2 (1)	C(21)—C(22)—C(23)—C(24)	−165.6 (6)

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