trans–cis S-Benzyl dithiocarbazate

In the crystal structure of the title compound, C₈H₁₀N₂S₂, the mol­ecules are linked by N—H...S hydrogen bonds between the imino group and the thione-S atoms to form a chain along the b axis. The di­thio­carb­azate moiety is rotated by 85.8 (2)° with respect to the phenyl ring.

S1. Comment

There has been much interest in S-methyl dithiocarbazate and its behaviour towards transition metals (Weber, 1979; Battistoni et al., 1971). According to NMR spectra (Gattegno & Giuliani, 1974), supported by theoretical studies (Andreocci et al., 1974), there are three types of conformations, viz. cis-cis, cis-trans and trans-cis, based on the twist angle along the N—C and C—S bonds, (0,0), (0,180) or (180,0). In the present structure the corresponding angles are 179.5 (2) and 0.6 (2)°, respectively. The cis-trans conformation is observed in unsubstituted esters and trans-cis in substituted esters. Two conformers of S-methyldithiocarbazate, namely cis-trans and trans-cis, were obtained in the solid state by recrystallization from ethanol at room temperature and from an ethanol-water mixture (2:3) below 273 K, respectively (Lanfredi et al., 1977; Mattes & Weber, 1980). In our study of the interaction of S-benzyl dithiocarbazate with dimethyl tin dichloride in acetonitrile, yellowish crystals of the title compound, (I), suitable for X-ray crystallographic analysis, were obtained. The compound is a trans-cis S-benzyldithiocarbazate. \sch

The C=S distance of 1.678 (3) Å agrees well with the values in the literature of 1.681 (5) Å (Mattes & Weber, 1980), and 1.679 (4) and 1.670 (6) Å (Lanfredi et al., 1977), being intermediate between the values of 1.82 Å for a C—S single bond and 1.56 Å for a C=S double bond (Suton, 1965). The C—N distance of 1.320 (3) Å is indicative of double-bond character. The bond angles S1—C8—S2 [125.4 (1)°] and N1—C8—S1 [113.5 (2)°] agree well with those observed for trans-cis S-methyl dithiocarbazate [125.5 (2) and 113.6 (3)°, respectively; Mattes & Weber, 1980], and are significantly different from the values of 116.2 (1) and 119.3 (1)°, respectively, observed for cis-trans S-methyl dithiocarbazate (Weber, 1979). This is the consequence of the participation of S2 in the hydrogen bond in the trans-cis conformer and of the change in the conformation of the S-ester groups.

The mean plane through N2/N1/C8/S2/S1/C7 is rotated by 85.8 (2)° with respect to the phenyl ring (Fig. 1). The H atom attached to the imino N has the potential to act as a hydrogen-bond donor. The intermolecular N—H···S hydrogen bonds involving the imino-N and thione-S atoms form a chain along the b axis (Fig. 2), as observed in trans-cis S-methyldithiocarbazate (Mattes & Weber, 1980). The N···S distance, N1···S2ⁱ = 3.345 (2) Å [symmetry code: (i) 1 − x, 1/2 + y, 3/2 − z], is significantly shorter than the same distance in S-methyl N,N-dimethyl dithiocarbazate [3.480 (4) Å; Lanfredi et al., 1977] and is comparable with the values of 3.389 (6) Å in S-methyl β-N-[4-(dimethylamino)benzylidene] dithiocarbazate (Zhao et al., 1997), 3.343 (2) and 3.490 (3) Å in dimethyl ammonium dithiocarbazate (Wahlberg, 1978a) and 3.348 (3) Å in diisopropylammonium dicarbazate (Wahlberg, 1978b). This value is at the upper end of the range summarized by Srinivasan & Chackko (1967). Moreover, atom H2B of the amino group is involved in two slightly longer N—H···S interactions [H2B···S2ⁱ = 3.413 (1) and N2····S2ⁱ = 3.780 (2) Å; H2B···S2ⁱⁱ = 3.295 (1) and N2····S2ⁱⁱ = 3.456 (2) Å; symmetry code: (ii) x, 3/2 − y, 1/2 + z], since it points towards the thione-S atoms of two different molecules.

S2. Experimental

Hydrazine hydrate (10 g) was mixed with potassium hydroxide (11.4 g) in 90% ethanol (70 ml) and cooled to 273 K in an ice bath. The addition of carbon disulfide (15.2 g) with constant stirring over a period of 1 h formed two layers. The light brown layer was separated, dissolved in cold 40% ethanol (60 ml) and kept in an ice bath. Benzyl chloride (25 g) was added dropwise with vigorous stirring of the mixture. The white product was formed after complete addition of the benzyl chloride. This product, (I), was filtered off and washed with water. After drying, it was recrystallized from benzene. An equimolar mixture of (I) and dimethyltin dichloride in ethanol after a few days of evaporation gave good crystals of (I), as shown by the infrared spectroscopy and elemental analysis.

S3. Refinement

Please provide details of H-atom refinement.

Computing details

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PARST (Nardelli, 1995).

Figures

	Fig. 1. The structure of (I) showing 50% probability displacement ellipsoids and the atom-numbering scheme. H atoms are drawn as small spheres of arbitrary radii.
	Fig. 2. The packing of the molecules of (I) viewed down the b axis [symmetry codes: (i) 1 − x, y + 1/2, 3/2 − z; (iii) 1 − x, y − 1/2, 3/2 − z]. Query symops.

trans-cis S-Benzyl dithiocarbazate

Crystal data

C8H10N2S2	F(000) = 416
Mr = 198.30	Dx = 1.348 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 19.7221 (9) Å	Cell parameters from 4301 reflections
b = 4.8605 (2) Å	θ = 3.1–28.4°
c = 10.2699 (5) Å	µ = 0.49 mm^−1
β = 97.121 (1)°	T = 293 K
V = 976.87 (8) Å^3	Parallelepiped, yellow
Z = 4	0.48 × 0.36 × 0.32 mm

Data collection

Siemens SMART CCD area-detector diffractometer	2398 independent reflections
Radiation source: fine-focus sealed tube	1760 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.061
Detector resolution: 8.33 pixels mm^-1	θmax = 28.3°, θmin = 3.1°
ω scans	h = −24→26
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	k = −6→6
Tmin = 0.798, Tmax = 0.859	l = −13→8
6578 measured reflections

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)] = 0.060	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.113	H-atom parameters constrained
S = 0.98	w = 1/[σ^2(Fo^2) + (0.1096P)^2 + 0.524P] where P = (Fo^2 + 2Fc^2)/3
2398 reflections	(Δ/σ)max < 0.001
109 parameters	Δρmax = 0.52 e Å^−3
0 restraints	Δρmin = −0.52 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
S1	0.29822 (3)	0.99793 (14)	0.62491 (6)	0.0456 (2)
S2	0.42999 (3)	0.70780 (16)	0.57742 (7)	0.0525 (3)
N1	0.41596 (11)	1.0695 (5)	0.7609 (2)	0.0466 (5)
H1A	0.4589	1.0470	0.7851	0.056*
N2	0.37887 (12)	1.2558 (5)	0.8294 (2)	0.0546 (6)
H2A	0.3359	1.2792	0.8058	0.066*
H2B	0.3992	1.3463	0.8949	0.066*
C1	0.19947 (12)	0.8645 (6)	0.4340 (2)	0.0444 (6)
C2	0.14408 (16)	0.7517 (8)	0.4816 (4)	0.0741 (10)
H2C	0.1503	0.6141	0.5449	0.089*
C3	0.07820 (17)	0.8417 (10)	0.4357 (5)	0.0915 (13)
H3A	0.0410	0.7680	0.4710	0.110*
C4	0.06799 (19)	1.0342 (9)	0.3408 (5)	0.0897 (14)
H4A	0.0239	1.0886	0.3085	0.108*
C5	0.1227 (2)	1.1481 (10)	0.2926 (4)	0.0893 (13)
H5A	0.1157	1.2837	0.2285	0.107*
C6	0.18876 (18)	1.0649 (8)	0.3379 (3)	0.0649 (8)
H6A	0.2257	1.1437	0.3037	0.078*
C7	0.27150 (13)	0.7767 (6)	0.4855 (3)	0.0502 (6)
H7A	0.3016	0.7990	0.4184	0.060*
H7B	0.2723	0.5853	0.5124	0.060*
C8	0.38581 (11)	0.9285 (5)	0.6602 (2)	0.0381 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0328 (3)	0.0610 (5)	0.0402 (4)	0.0037 (2)	−0.0066 (3)	−0.0070 (3)
S2	0.0378 (4)	0.0730 (5)	0.0437 (4)	0.0121 (3)	−0.0070 (3)	−0.0074 (3)
N1	0.0361 (10)	0.0633 (14)	0.0372 (11)	−0.0012 (9)	−0.0074 (8)	−0.0028 (10)
N2	0.0470 (12)	0.0669 (16)	0.0473 (13)	0.0027 (10)	−0.0044 (10)	−0.0148 (10)
C1	0.0367 (11)	0.0523 (15)	0.0409 (14)	0.0018 (10)	−0.0087 (10)	−0.0073 (11)
C2	0.0501 (17)	0.088 (3)	0.082 (3)	−0.0067 (15)	0.0010 (17)	0.0134 (18)
C3	0.0406 (16)	0.114 (4)	0.118 (4)	−0.0085 (19)	0.005 (2)	−0.009 (3)
C4	0.053 (2)	0.106 (3)	0.101 (3)	0.0229 (19)	−0.028 (2)	−0.028 (3)
C5	0.087 (3)	0.102 (3)	0.069 (2)	0.030 (2)	−0.026 (2)	0.008 (2)
C6	0.0606 (17)	0.077 (2)	0.0543 (17)	0.0070 (15)	−0.0033 (14)	0.0081 (15)
C7	0.0386 (12)	0.0584 (17)	0.0497 (15)	0.0031 (10)	−0.0094 (11)	−0.0081 (12)
C8	0.0346 (10)	0.0493 (14)	0.0283 (11)	−0.0019 (9)	−0.0046 (9)	0.0064 (9)

Geometric parameters (Å, º)

S1—C8	1.753 (2)	C2—C3	1.396 (5)
S1—C7	1.816 (3)	C2—H2C	0.9300
S2—C8	1.678 (3)	C3—C4	1.348 (7)
N1—C8	1.320 (3)	C3—H3A	0.9300
N1—N2	1.406 (3)	C4—C5	1.359 (7)
N1—H1A	0.8600	C4—H4A	0.9300
N2—H2A	0.8600	C5—C6	1.388 (5)
N2—H2B	0.8600	C5—H5A	0.9300
C1—C2	1.366 (4)	C6—H6A	0.9300
C1—C6	1.384 (5)	C7—H7A	0.9700
C1—C7	1.515 (3)	C7—H7B	0.9700
C8—S1—C7	103.4 (1)	C3—C4—H4A	120.3
C8—N1—N2	121.0 (2)	C5—C4—H4A	120.3
C8—N1—H1A	119.5	C4—C5—C6	120.9 (4)
N2—N1—H1A	119.5	C4—C5—H5A	119.5
N1—N2—H2A	120.0	C6—C5—H5A	119.5
N1—N2—H2B	120.0	C1—C6—C5	119.8 (4)
H2A—N2—H2B	120.0	C1—C6—H6A	120.1
C2—C1—C6	118.7 (3)	C5—C6—H6A	120.1
C2—C1—C7	121.3 (3)	C1—C7—S1	106.05 (19)
C6—C1—C7	120.1 (3)	C1—C7—H7A	110.5
C1—C2—C3	120.4 (4)	S1—C7—H7A	110.5
C1—C2—H2C	119.8	C1—C7—H7B	110.5
C3—C2—H2C	119.8	S1—C7—H7B	110.5
C4—C3—C2	120.7 (4)	H7A—C7—H7B	108.7
C4—C3—H3A	119.7	N1—C8—S2	121.15 (18)
C2—C3—H3A	119.7	N1—C8—S1	113.50 (19)
C3—C4—C5	119.5 (3)	S2—C8—S1	125.35 (14)
C6—C1—C2—C3	−1.3 (6)	C2—C1—C7—S1	−88.5 (3)
C7—C1—C2—C3	178.0 (3)	C6—C1—C7—S1	90.7 (3)
C1—C2—C3—C4	2.3 (7)	C8—S1—C7—C1	−169.7 (2)
C2—C3—C4—C5	−2.2 (7)	N2—N1—C8—S2	179.5 (2)
C3—C4—C5—C6	1.3 (7)	N2—N1—C8—S1	−0.3 (3)
C2—C1—C6—C5	0.4 (5)	C7—S1—C8—N1	−179.6 (2)
C7—C1—C6—C5	−178.9 (3)	C7—S1—C8—S2	0.6 (2)
C4—C5—C6—C1	−0.4 (6)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···S1	0.86	2.35	2.772 (2)	110
N1—H1A···S2^i	0.86	2.58	3.345 (2)	149

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