The 4-(3-chloro-4-methyl­phen­yl)-1,2,3,5-dithia­diazol-3-yl radical

Abstract

The asymmetric unit of the title compound, C₈H₆ClN₂S₂, comprises two mol­ecules forming a dimer via π–π stacking inter­actions [centroid–centroid distance = 3.634 (10) Å] and intra­dimer S⋯S contacts [3.012 (4) and 3.158 (4) Å] between the two mol­ecules in a cis-antarafacial arrangement.

Related literature

For the properties of the 4-methyl­phenyl dithia­diazolyl radical, see: Boeré et al. (1992 ▶). For similar phenyl dithia­diazolyl radical structures, see: Allen et al. (2009 ▶); Clarke et al. (2010 ▶). For notes on the configurations adopted by phenyl dithia­diazolyl radicals in their crystal structures, see: Aherne et al. (1993 ▶).

Experimental

Crystal data

• C₈H₆ClN₂S₂

• M _r = 229.72

• Monoclinic,

• a = 5.937 (3) Å

• b = 13.407 (3) Å

• c = 11.573 (3) Å

• β = 95.87 (4)°

• V = 916.3 (6) ų

• Z = 4

• Mo Kα radiation

• μ = 0.82 mm⁻¹

• T = 150 K

• 0.25 × 0.18 × 0.15 mm

Data collection

• Rigaku AFC-6S diffractometer

• 1655 measured reflections

• 1499 independent reflections

• 1054 reflections with I > 2σ(I)

• R _int = 0.103

• θ_max = 24.0°

• 3 standard reflections every 200 reflections intensity decay: none

Refinement

• R[F ² > 2σ(F ²)] = 0.042

• wR(F ²) = 0.098

• S = 1.09

• 1499 reflections

• 237 parameters

• 1 restraint

• H-atom parameters constrained

• Δρ_max = 0.44 e Å⁻³

• Δρ_min = −0.38 e Å⁻³

• Absolute structure: Flack (1983 ▶), 169 Friedel pairs

• Flack parameter: −0.16 (19)

Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1991 ▶); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN (Molec­ular Structure Corporation, 1989 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: WinGX publication routines (Farrugia, 1999 ▶).

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

supplementary crystallographic information

Comment

As observed in similar structures (Aherne et al. 1993; Allen et al. 2009 and Clarke et al. 2010), within the planar CS₂N₂ rings the C—N and S—N bonds distances exhibit intermediate values between those of standard single and double bonds indicating the delocalized nature of the radical about the N—C—N fragment. Though the S—S distance is unusually long it is comparable to similar phenyl dithiadiazolyl radical structures. Intradimer contacts include π-π stacking interactions between the aryl rings of the 3-chloro-4-methylphenyl dithiadiazolyl radicals with a centroid-to-centroid distance of 3.634 (10) Å, and two cis-antarafacial S···S contacts (S1···S3 = 3.012 (4) Å; S2···S4 = 3.158 (4) Å).

Experimental

Lithium hexamethyldisilazane (1.67 g, 0.01 mol) was added to 3-chloro-4-methylbenzonitrile (1.51 g, 0.01 mol) in ethanol (40 ml) and stirred for 3 h. To the resulting yellow solution SCl₂ (1.27 ml, 0.02 mol) and diethyl ether (25 ml) was added producing a red solution containing the 3-chloro-4-methylphenyl dithiadiazolyl cation (yield: 91°). The radical was formed upon reduction of the cation (1.43 g, 5 mmol) with a Zn(Cu) couple (0.18 g, 2.8 mmol) as the reducing agent in THF (25 ml). Crystals suitable for X-ray crystallography were grown via sublimation of the product under vacuum at 373 K.

Refinement

H atoms were positioned geometrically and refined as riding on their parent atoms, with C—H = 0.930 Å and Uiso(H) = 1.2Ueq(C). Methyl hydrogen atoms were modeled in a similar fashion C—H = 0.960 Å and Uiso(H) = 1.5Ueq(C). The most disagreeable reflections were omitted; six reflections exhibiting a Δ(F²) value greater than 5 su were removed. The absolute structure was determined with a Flack (1983) parameter of -0.16 (19), using 169 reflections.

Figures

Fig. 1.

The structure of the title compound with displacement ellipsoids drawn at the 50% probability level showing S···S contacts (dashed lines).

Crystal data

C8H6ClN2S2	F(000) = 468
Mr = 229.72	Dx = 1.665 Mg m−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 20 reflections
a = 5.937 (3) Å	θ = 3.0–11.0°
b = 13.407 (3) Å	µ = 0.82 mm−1
c = 11.573 (3) Å	T = 150 K
β = 95.87 (4)°	Prism, colourless
V = 916.3 (6) Å3	0.25 × 0.18 × 0.15 mm
Z = 4

Data collection

Rigaku AFC-6S diffractometer	θmax = 24.0°, θmin = 3.5°
graphite	h = 0→6
ω scans	k = 0→15
1655 measured reflections	l = −13→13
1499 independent reflections	3 standard reflections every 200 reflections
1054 reflections with I > 2σ(I)	intensity decay: none
Rint = 0.103

Refinement

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.042	H-atom parameters constrained
wR(F2) = 0.098	w = 1/[σ2(Fo2) + (0.0132P)2 + 2.2783P] where P = (Fo2 + 2Fc2)/3
S = 1.09	(Δ/σ)max < 0.001
1499 reflections	Δρmax = 0.44 e Å−3
237 parameters	Δρmin = −0.38 e Å−3
1 restraint	Absolute structure: Flack (1983), 169 Friedel pairs
Primary atom site location: structure-invariant direct methods	Flack parameter: −0.16 (19)

Special details

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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
S2	0.5244 (5)	0.3269 (2)	−0.1014 (2)	0.0271 (7)
S1	0.2324 (4)	0.3359 (2)	−0.0142 (2)	0.0263 (7)
N2	0.6580 (15)	0.4154 (7)	−0.0244 (7)	0.025 (2)
N1	0.3323 (14)	0.4260 (6)	0.0724 (7)	0.024 (2)
C1	0.5430 (17)	0.4558 (8)	0.0533 (9)	0.024 (2)
C2	0.6477 (16)	0.5355 (8)	0.1287 (8)	0.017 (2)
C6	0.9463 (14)	0.6549 (7)	0.1743 (7)	0.019 (2)
H6	1.0823	0.6826	0.1567	0.023*
C7	0.8533 (15)	0.5770 (8)	0.1066 (8)	0.021 (2)
H7	0.9289	0.5524	0.046	0.025*
C3	0.5398 (15)	0.5719 (7)	0.2224 (8)	0.020 (2)
H3	0.4034	0.5447	0.2401	0.024*
C5	0.8434 (15)	0.6933 (8)	0.2681 (8)	0.021 (2)
C8	0.9427 (16)	0.7782 (8)	0.3392 (8)	0.026 (2)
H8A	1.061	0.8085	0.3007	0.039*
H8B	1.004	0.7542	0.414	0.039*
H8C	0.827	0.8267	0.3488	0.039*
C4	0.6413 (15)	0.6499 (7)	0.2885 (7)	0.018 (2)
Cl1	0.5049 (4)	0.6884 (2)	0.4074 (2)	0.0278 (7)
S3	0.3937 (5)	0.1726 (2)	0.1531 (2)	0.0302 (7)
S4	0.7080 (4)	0.1669 (2)	0.0853 (2)	0.0293 (7)
Cl2	0.5678 (4)	0.47502 (19)	0.6289 (2)	0.0259 (6)
N4	0.8253 (12)	0.2511 (6)	0.1763 (7)	0.0208 (19)
C10	0.7757 (15)	0.3556 (7)	0.3403 (7)	0.018 (2)
C15	0.9878 (16)	0.4033 (8)	0.3377 (8)	0.025 (2)
H15	1.079	0.3871	0.2797	0.031*
C9	0.6891 (16)	0.2851 (8)	0.2539 (8)	0.021 (2)
C12	0.7250 (15)	0.4511 (7)	0.5142 (7)	0.014 (2)
C11	0.6480 (15)	0.3831 (7)	0.4301 (8)	0.022 (2)
H11	0.506	0.3544	0.4332	0.027*
C14	1.0611 (14)	0.4740 (8)	0.4206 (7)	0.023 (2)
H14	1.2004	0.5047	0.4161	0.027*
C13	0.9336 (16)	0.5008 (7)	0.5106 (8)	0.020 (2)
C16	1.0139 (17)	0.5799 (8)	0.6005 (9)	0.029 (3)
H16A	0.8912	0.6245	0.6114	0.043*
H16B	1.1369	0.6169	0.5738	0.043*
H16C	1.0639	0.5482	0.673	0.043*
N3	0.4777 (14)	0.2515 (7)	0.2537 (7)	0.025 (2)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
S2	0.0299 (17)	0.0296 (16)	0.0226 (14)	−0.0059 (15)	0.0067 (12)	−0.0050 (12)
S1	0.0193 (14)	0.0277 (15)	0.0311 (15)	−0.0007 (13)	−0.0007 (12)	−0.0104 (14)
N2	0.031 (5)	0.025 (5)	0.022 (4)	0.001 (4)	0.012 (4)	0.001 (4)
N1	0.019 (5)	0.026 (5)	0.026 (5)	0.000 (4)	0.001 (4)	−0.011 (4)
C1	0.018 (5)	0.022 (6)	0.031 (6)	−0.013 (5)	−0.005 (4)	0.006 (5)
C2	0.015 (5)	0.019 (6)	0.018 (5)	0.007 (4)	0.002 (4)	0.001 (4)
C6	0.008 (4)	0.025 (7)	0.023 (5)	−0.002 (4)	−0.001 (4)	0.004 (4)
C7	0.022 (6)	0.027 (6)	0.014 (5)	0.007 (5)	−0.002 (4)	0.007 (5)
C3	0.015 (5)	0.012 (5)	0.032 (6)	0.001 (4)	−0.005 (5)	0.007 (5)
C5	0.015 (5)	0.018 (6)	0.030 (5)	0.003 (5)	−0.007 (4)	0.008 (5)
C8	0.022 (5)	0.031 (6)	0.024 (5)	−0.001 (5)	−0.002 (5)	−0.004 (5)
C4	0.016 (5)	0.026 (7)	0.012 (5)	0.013 (5)	0.000 (4)	−0.003 (5)
Cl1	0.0259 (13)	0.0279 (17)	0.0310 (14)	−0.0008 (13)	0.0090 (10)	−0.0078 (13)
S3	0.0353 (15)	0.0314 (17)	0.0242 (13)	−0.0117 (14)	0.0047 (11)	−0.0063 (13)
S4	0.0318 (15)	0.0270 (17)	0.0287 (14)	0.0049 (14)	0.0005 (12)	−0.0049 (13)
Cl2	0.0266 (13)	0.0286 (16)	0.0240 (13)	−0.0004 (14)	0.0094 (10)	−0.0073 (13)
N4	0.019 (4)	0.019 (5)	0.025 (5)	0.005 (4)	0.003 (4)	−0.011 (4)
C10	0.015 (5)	0.031 (7)	0.008 (4)	0.008 (5)	−0.003 (4)	0.006 (4)
C15	0.028 (6)	0.028 (6)	0.022 (5)	0.005 (5)	0.010 (4)	0.008 (5)
C9	0.019 (5)	0.027 (6)	0.017 (5)	−0.003 (5)	0.001 (4)	0.010 (5)
C12	0.018 (5)	0.012 (5)	0.012 (5)	0.009 (4)	0.000 (4)	0.002 (4)
C11	0.013 (5)	0.026 (6)	0.026 (5)	0.001 (5)	−0.008 (4)	0.005 (5)
C14	0.012 (5)	0.034 (6)	0.022 (5)	−0.004 (5)	0.001 (4)	0.002 (5)
C13	0.023 (6)	0.013 (5)	0.024 (6)	−0.003 (4)	−0.003 (4)	0.002 (4)
C16	0.029 (6)	0.021 (6)	0.037 (6)	−0.005 (5)	0.008 (5)	−0.012 (5)
N3	0.023 (5)	0.030 (5)	0.024 (4)	−0.013 (4)	0.011 (4)	−0.008 (4)

Geometric parameters (Å, °)

S2—N2	1.639 (10)	S3—N3	1.613 (9)
S2—S1	2.096 (3)	S3—S4	2.098 (4)
S1—N1	1.641 (8)	S4—N4	1.648 (8)
N2—C1	1.302 (13)	Cl2—C12	1.728 (9)
N1—C1	1.352 (13)	N4—C9	1.348 (12)
C1—C2	1.476 (13)	C10—C11	1.398 (13)
C2—C7	1.388 (13)	C10—C15	1.415 (13)
C2—C3	1.403 (13)	C10—C9	1.432 (13)
C6—C7	1.387 (13)	C15—C14	1.387 (13)
C6—C5	1.397 (12)	C15—H15	0.93
C6—H6	0.93	C9—N3	1.333 (12)
C7—H7	0.93	C12—C11	1.377 (13)
C3—C4	1.395 (13)	C12—C13	1.411 (13)
C3—H3	0.93	C11—H11	0.93
C5—C4	1.375 (12)	C14—C13	1.396 (13)
C5—C8	1.491 (14)	C14—H14	0.93
C8—H8A	0.96	C13—C16	1.528 (13)
C8—H8B	0.96	C16—H16A	0.96
C8—H8C	0.96	C16—H16B	0.96
C4—Cl1	1.746 (8)	C16—H16C	0.96
N2—S2—S1	94.3 (3)	N3—S3—S4	94.2 (3)
N1—S1—S2	94.1 (3)	N4—S4—S3	94.0 (3)
C1—N2—S2	114.7 (7)	C9—N4—S4	114.5 (7)
C1—N1—S1	113.6 (7)	C11—C10—C15	116.6 (9)
N2—C1—N1	123.3 (10)	C11—C10—C9	120.6 (8)
N2—C1—C2	119.3 (9)	C15—C10—C9	122.7 (8)
N1—C1—C2	117.3 (9)	C14—C15—C10	120.7 (8)
C7—C2—C3	118.8 (9)	C14—C15—H15	119.6
C7—C2—C1	120.4 (9)	C10—C15—H15	119.6
C3—C2—C1	120.7 (9)	N3—C9—N4	120.9 (9)
C7—C6—C5	122.4 (9)	N3—C9—C10	119.7 (8)
C7—C6—H6	118.8	N4—C9—C10	119.4 (8)
C5—C6—H6	118.8	C11—C12—C13	121.4 (8)
C6—C7—C2	120.3 (9)	C11—C12—Cl2	119.9 (7)
C6—C7—H7	119.9	C13—C12—Cl2	118.7 (7)
C2—C7—H7	119.9	C12—C11—C10	122.3 (9)
C4—C3—C2	118.6 (9)	C12—C11—H11	118.9
C4—C3—H3	120.7	C10—C11—H11	118.9
C2—C3—H3	120.7	C15—C14—C13	122.4 (9)
C4—C5—C6	115.8 (9)	C15—C14—H14	118.8
C4—C5—C8	122.1 (9)	C13—C14—H14	118.8
C6—C5—C8	122.1 (9)	C14—C13—C12	116.5 (9)
C5—C8—H8A	109.5	C14—C13—C16	122.1 (9)
C5—C8—H8B	109.5	C12—C13—C16	121.4 (8)
H8A—C8—H8B	109.5	C13—C16—H16A	109.5
C5—C8—H8C	109.5	C13—C16—H16B	109.5
H8A—C8—H8C	109.5	H16A—C16—H16B	109.5
H8B—C8—H8C	109.5	C13—C16—H16C	109.5
C5—C4—C3	124.0 (8)	H16A—C16—H16C	109.5
C5—C4—Cl1	119.5 (7)	H16B—C16—H16C	109.5
C3—C4—Cl1	116.4 (7)	C9—N3—S3	116.4 (7)