Tetragonal polymorphic modification of tetrakis­(N,N-diethyl­di­thio­carbam­ato-S,S')­tellurium(IV)

During an investigation of the W/Te/Br₂ system, we prepared crystals of the title compound, C₂₀H₄₀N₄S₈Te, from aceto­nitrile solution by slow addition of diethyl ether. It appeared to be a new tetragonal modification. The calculated density of the tetragonal modification (1.513 Mg m^-3) is slightly greater than found for the known orthorhombic modification (1.46 Mg m^-3). The bond distances and angles are practically the same.

S1. Comment

Previously, the crystal structure of the title compound, (I), was investigated (Husebye & Svaeren, 1973) and an orthorhombic unit cell with space group Pn2₁a was found. Orthorhombic crystals were prepared by crystallization from benzene solution. \scheme

During an investigation of the W/Te/Br₂ system, we prepared the title compound. Crystals were obtained from acetonitrile solution by slow addition of diethyl ether. Chemical composition and molecular structure are the same as previously, but the crystal structure appeared to be tetragonal, space group P4₃2₁2. This means that we have found a new tetragonal modification of Te(S₂CNEt₂)₄.

In the previously known orthorhombic modification, there are two crystallographically independent molecules both in general positions. In our case, we have only one molecule lying on a twofold axis. The bond lengths and angles are practically the same. As previously, the Te atom is coordinated by four bidentate dithiocarbamate ligands. The coordination polyhedron around Te is a flattened square prism.

The possible reason for formation of two different modifications is the nature of the solvent used for preparation of the crystals: non-polar (C₆H₆) for orthorhombic modification and polar (CH₃CN + Et₂O) for tetragonal one.

The calculated density of the tetragonal modification (1.51 Mg m⁻³) is slightly greater than found for the orthorhombic crystals (1.46 Mg m⁻³).

S2. Experimental

The title compound was prepared during the investigation of a high-temperature reaction between W, Te and Br₂. The product was heated with NaS₂CNEt₂ at 453 K. The product was recrystallized from acetonitrile solution and after slow addition of diethyl ether, octahedral-shaped orange crystals were obtained.

Computing details

Data collection: STADI4 (Stoe, 1998); cell refinement: STADI4; data reduction: X-RED (Stoe, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: local programs; software used to prepare material for publication: local programs.

tetracis(diethyldithiocarbamato)tellurium(IV)

Crystal data

C20H40N4S8Te	Dx = 1.513 Mg m^−3
Mr = 720.64	Mo Kα radiation, λ = 0.71073 Å
Tetragonal, P43212	Cell parameters from 32 reflections
Hall symbol: P 41n 2abw	θ = 11.2–14.4°
a = 10.3970 (15) Å	µ = 1.49 mm^−1
c = 29.262 (6) Å	T = 212 K
V = 3163.2 (9) Å^3	Octahedron, orange
Z = 4	0.33 × 0.30 × 0.28 mm
F(000) = 1472

Data collection

Stoe Stadi-4 diffractometer	2527 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.021
Graphite monochromator	θmax = 25.0°, θmin = 2.1°
ω scans	h = 0→12
Absorption correction: empirical (using intensity measurements) X-RED (Stoe & Cie, 1998)	k = 0→12
Tmin = 0.596, Tmax = 0.660	l = 0→34
3161 measured reflections	3 standard reflections every 60 min
2791 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)] = 0.029	H-atom parameters constrained
wR(F^2) = 0.057	w = 1/[σ^2(Fo^2) + (0.0079P)^2 + 5.2275P] where P = (Fo^2 + 2Fc^2)/3
S = 1.13	(Δ/σ)max = 0.001
2791 reflections	Δρmax = 0.29 e Å^−3
150 parameters	Δρmin = −0.28 e Å^−3
0 restraints	Absolute structure: Flack (1983), 1094 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.06 (3)

Special details

Experimental. none

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
Te1	0.43761 (3)	0.56239 (3)	0.7500	0.02151 (9)
S11	0.42914 (12)	0.39940 (10)	0.82649 (4)	0.0287 (3)
S12	0.66612 (11)	0.53125 (12)	0.79778 (4)	0.0339 (3)
S21	0.19313 (11)	0.46936 (11)	0.76072 (4)	0.0329 (3)
S22	0.27112 (11)	0.65413 (13)	0.68924 (4)	0.0336 (3)
C1	0.5912 (4)	0.4240 (4)	0.83389 (13)	0.0269 (10)
N1	0.6578 (4)	0.3632 (4)	0.86666 (13)	0.0351 (10)
C11	0.5945 (6)	0.2774 (5)	0.89921 (17)	0.0474 (15)
H11A	0.6457	0.1987	0.9021	0.047*
H11B	0.5101	0.2532	0.8870	0.047*
C12	0.5765 (7)	0.3350 (6)	0.94570 (19)	0.0697 (19)
H12A	0.6597	0.3468	0.9601	0.070*
H12B	0.5242	0.2780	0.9642	0.070*
H12C	0.5338	0.4176	0.9429	0.070*
C13	0.7988 (5)	0.3767 (5)	0.87132 (18)	0.0468 (15)
H13A	0.8220	0.3683	0.9036	0.047*
H13B	0.8239	0.4631	0.8613	0.047*
C14	0.8729 (5)	0.2793 (6)	0.8442 (2)	0.0552 (16)
H14A	0.8476	0.1934	0.8535	0.055*
H14B	0.9642	0.2908	0.8495	0.055*
H14C	0.8547	0.2906	0.8119	0.055*
C2	0.1502 (4)	0.5677 (5)	0.71586 (14)	0.0277 (10)
N2	0.0285 (3)	0.5801 (4)	0.70322 (12)	0.0330 (10)
C21	−0.0123 (5)	0.6597 (5)	0.66391 (16)	0.0398 (13)
H21A	−0.0754	0.6119	0.6457	0.040*
H21B	0.0624	0.6771	0.6444	0.040*
C22	−0.0710 (7)	0.7863 (6)	0.67908 (19)	0.0628 (16)
H22A	−0.1558	0.7708	0.6917	0.063*
H22B	−0.0781	0.8436	0.6530	0.063*
H22C	−0.0167	0.8254	0.7022	0.063*
C23	−0.0755 (5)	0.5178 (5)	0.72878 (16)	0.0379 (12)
H23A	−0.1541	0.5690	0.7252	0.038*
H23B	−0.0531	0.5177	0.7613	0.038*
C24	−0.1032 (5)	0.3820 (5)	0.71424 (19)	0.0484 (15)
H24A	−0.1259	0.3808	0.6821	0.048*
H24B	−0.1742	0.3482	0.7321	0.048*
H24C	−0.0275	0.3293	0.7191	0.048*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Te1	0.01978 (11)	0.01978 (11)	0.02498 (18)	−0.00109 (17)	−0.00064 (13)	−0.00064 (13)
S11	0.0280 (6)	0.0259 (6)	0.0324 (6)	−0.0013 (5)	0.0005 (5)	0.0031 (4)
S12	0.0259 (6)	0.0408 (8)	0.0349 (6)	−0.0055 (5)	−0.0031 (5)	0.0047 (6)
S21	0.0227 (6)	0.0366 (7)	0.0394 (7)	−0.0056 (5)	−0.0019 (5)	0.0107 (5)
S22	0.0223 (6)	0.0440 (7)	0.0346 (7)	−0.0038 (5)	−0.0011 (5)	0.0122 (6)
C1	0.031 (3)	0.024 (2)	0.0255 (19)	−0.0011 (19)	−0.0053 (18)	−0.008 (2)
N1	0.039 (3)	0.034 (2)	0.033 (2)	0.0026 (18)	−0.0145 (19)	0.0010 (19)
C11	0.055 (4)	0.041 (3)	0.046 (3)	0.001 (3)	−0.016 (3)	0.016 (3)
C12	0.077 (5)	0.080 (5)	0.052 (4)	−0.003 (4)	0.009 (4)	0.009 (3)
C13	0.039 (3)	0.053 (3)	0.048 (3)	0.002 (3)	−0.024 (3)	0.002 (3)
C14	0.036 (3)	0.062 (4)	0.068 (4)	0.006 (3)	−0.014 (3)	−0.006 (3)
C2	0.026 (2)	0.032 (2)	0.025 (2)	0.001 (2)	−0.0001 (18)	0.000 (2)
N2	0.021 (2)	0.046 (2)	0.032 (2)	−0.0006 (19)	−0.0015 (16)	0.006 (2)
C21	0.026 (3)	0.063 (4)	0.030 (3)	0.000 (3)	−0.006 (2)	0.009 (3)
C22	0.073 (4)	0.063 (4)	0.052 (3)	0.008 (4)	0.005 (4)	0.015 (3)
C23	0.018 (2)	0.058 (3)	0.037 (3)	−0.009 (2)	0.003 (2)	0.002 (2)
C24	0.038 (3)	0.061 (4)	0.047 (3)	−0.009 (3)	0.003 (3)	−0.005 (3)

Geometric parameters (Å, º)

Te1—S11^i	2.8088 (11)	S22—C2	1.730 (5)
Te1—S11	2.8088 (11)	C1—N1	1.341 (5)
Te1—S12^i	2.7758 (12)	N1—C11	1.462 (7)
Te1—S12	2.7758 (13)	N1—C13	1.479 (6)
Te1—S21	2.7377 (12)	C11—C12	1.498 (7)
Te1—S21^i	2.7377 (12)	C13—C14	1.501 (7)
Te1—S22	2.6584 (13)	C2—N2	1.325 (5)
Te1—S22^i	2.6584 (13)	N2—C21	1.479 (6)
S11—C1	1.718 (4)	N2—C23	1.466 (6)
S12—C1	1.723 (5)	C21—C22	1.517 (8)
S21—C2	1.723 (5)	C23—C24	1.503 (7)
S11^i—Te1—S11	132.28 (5)	S22^i—Te1—S21	79.65 (4)
S12^i—Te1—S11^i	63.58 (3)	S22—Te1—S21^i	79.65 (4)
S12—Te1—S11^i	83.60 (4)	S22^i—Te1—S21^i	66.35 (4)
S12^i—Te1—S11	83.60 (4)	S22—Te1—S22^i	88.86 (6)
S12—Te1—S11	63.58 (3)	C1—S11—Te1	88.86 (15)
S12^i—Te1—S12	93.10 (5)	C1—S12—Te1	89.85 (14)
S21—Te1—S11^i	131.50 (3)	C2—S21—Te1	86.74 (15)
S21^i—Te1—S11^i	70.51 (3)	C2—S22—Te1	89.17 (15)
S21—Te1—S11	70.51 (3)	S11—C1—S12	117.5 (2)
S21^i—Te1—S11	131.50 (3)	N1—C1—S11	121.8 (4)
S21—Te1—S12^i	82.16 (4)	N1—C1—S12	120.7 (4)
S21^i—Te1—S12^i	134.09 (3)	C1—N1—C11	121.4 (4)
S21—Te1—S12	134.09 (3)	C1—N1—C13	122.2 (4)
S21^i—Te1—S12	82.16 (4)	C11—N1—C13	116.4 (4)
S21—Te1—S21^i	132.01 (5)	N1—C11—C12	113.8 (5)
S22—Te1—S11^i	81.30 (4)	N1—C13—C14	113.3 (4)
S22^i—Te1—S11^i	136.80 (4)	S21—C2—S22	117.6 (2)
S22—Te1—S11	136.80 (4)	N2—C2—S21	121.2 (4)
S22^i—Te1—S11	81.30 (4)	N2—C2—S22	121.2 (4)
S22—Te1—S12^i	92.64 (4)	C2—N2—C21	123.0 (4)
S22^i—Te1—S12^i	159.41 (4)	C2—N2—C23	121.3 (4)
S22—Te1—S12	159.41 (4)	C23—N2—C21	115.7 (4)
S22^i—Te1—S12	92.64 (4)	N2—C21—C22	111.9 (4)
S22—Te1—S21	66.35 (4)	N2—C23—C24	114.3 (4)

Symmetry code: (i) −y+1, −x+1, −z+3/2.