2-Chloro­ethyl ethyl sulfide: a mustard gas analogue

2-Chloro­ethyl ethyl sulfide (Cl-CH₂-CH₂-S-CH₂-CH₃ or C₄H₉ClS) is used as an analogue for mustard gas in biomedical studies. The Cl-C-C-S and the two C-C-S-C torsion angles are -177.38 (9), 83.17 (14) and 73.81 (16)°, respectively, and are similar to values that have been predicted, by ab initio quantum calculations, for the corresponding parameters in mustard gas. There are no strong intermolecular interactions, and the packing in the crystal structure bears some resemblance to hexagonal close packing.

Key indicators

• Single-crystal X-ray study
• T = 150 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.024
• wR factor = 0.064
• Data-to-parameter ratio = 25.7

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT063_ALERT_3_B Crystal Probably too Large for Beam Size .......       1.00 mm

Alert level C
ABSTM02_ALERT_3_C  The ratio of expected to reported Tmax/Tmin(RR') is < 0.90
            Tmin and Tmax reported:      0.352     0.790
            Tmin' and Tmax expected:      0.455     0.791
            RR' =      0.774
            Please check that your absorption correction is appropriate.
CRYSR01_ALERT_1_C  _exptl_crystal_size_rad not in the CIF when expected.
PLAT061_ALERT_3_C Tmax/Tmin Range Test RR' too Large .............       0.77

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           28.26
           From the CIF: _reflns_number_total               1441
           Count of symmetry unique reflns          894
           Completeness (_total/calc)            161.19%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured       547
           Fraction of Friedel pairs measured     0.612
           Are heavy atom types Z>Si present          yes

   0 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   3 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT; data reduction: SAINT (Bruker, 2002); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: CRYSTALS (Watkin et al., 2003); molecular graphics: XP (Sheldrick, 1997); software used to prepare material for publication: CRYSTALS, enCIFer (CCDC, 2002), PLATON (Spek, 2003) and WinGX (Farrugia, 1999).

2-Chloroethyl ethyl sulfide

Crystal data

C4H9ClS	F(000) = 264
Mr = 124.63	Dx = 1.287 Mg m^−3
Orthorhombic, Pna21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2n	Cell parameters from 3540 reflections
a = 15.343 (3) Å	θ = 3–29°
b = 8.5760 (14) Å	µ = 0.78 mm^−1
c = 4.8863 (8) Å	T = 150 K
V = 642.96 (18) Å^3	Cylinder, colourless
Z = 4	1.00 × 0.30 × 0.30 mm

Data collection

Bruker SMART APEX diffractometer	1313 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.03
ω scans	θmax = 28.3°, θmin = 2.7°
Absorption correction: multi-scan SADABS (Sheldrick, 2002)	h = −19→19
Tmin = 0.352, Tmax = 0.790	k = −9→11
4048 measured reflections	l = −6→6
1441 independent reflections

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)] = 0.024	H-atom parameters constrained
wR(F^2) = 0.064	w = 1/[σ^2(Fo^2) + (0.0194P)^2 + 0.136P] where P = (Fo^2 + 2Fc^2)/3 (SHELXL97; Sheldrick, 1997)
S = 1.01	(Δ/σ)max = 0.001
1438 reflections	Δρmax = 0.36 e Å^−3
56 parameters	Δρmin = −0.25 e Å^−3
1 restraint	Absolute structure: Flack (1983); 597 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.23 (12)

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

	x	y	z	Uiso*/Ueq
Cl1	0.44869 (3)	0.12110 (5)	0.13095 (14)	0.0353
C2	0.37514 (12)	0.1959 (2)	0.3892 (4)	0.0315
C3	0.32202 (11)	0.0630 (2)	0.5064 (4)	0.0276
S4	0.24368 (3)	0.13448 (5)	0.75570 (15)	0.0359
C5	0.15538 (12)	0.1954 (2)	0.5312 (4)	0.0379
C6	0.10405 (12)	0.0620 (3)	0.4094 (5)	0.0441
H21	0.4096	0.2463	0.5388	0.0377*
H22	0.3352	0.2745	0.3049	0.0377*
H31	0.3621	−0.0130	0.5975	0.0331*
H32	0.2901	0.0096	0.3545	0.0331*
H51	0.1145	0.2622	0.6391	0.0455*
H52	0.1809	0.2579	0.3780	0.0455*
H61	0.0569	0.1043	0.2890	0.0529*
H62	0.0774	−0.0012	0.5598	0.0529*
H63	0.1438	−0.0055	0.2987	0.0529*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0313 (2)	0.0445 (2)	0.0302 (2)	0.00303 (18)	0.0016 (2)	−0.0013 (2)
C2	0.0350 (9)	0.0308 (9)	0.0286 (9)	0.0011 (7)	0.0035 (8)	−0.0035 (8)
C3	0.0295 (8)	0.0270 (8)	0.0263 (8)	0.0039 (6)	−0.0012 (8)	−0.0022 (7)
S4	0.0336 (2)	0.0474 (3)	0.0268 (2)	0.0031 (2)	0.0006 (2)	−0.0039 (3)
C5	0.0326 (9)	0.0307 (9)	0.0505 (12)	0.0075 (8)	−0.0020 (9)	−0.0017 (8)
C6	0.0307 (10)	0.0419 (11)	0.0598 (15)	0.0010 (8)	−0.0077 (11)	−0.0026 (10)

Geometric parameters (Å, º)

Cl1—C2	1.810 (2)	S4—C5	1.820 (2)
C2—H22	1.000	C5—H52	1.000
C2—H21	1.000	C5—H51	1.000
C2—C3	1.513 (3)	C5—C6	1.512 (3)
C3—H32	1.000	C6—H63	1.000
C3—H31	1.000	C6—H62	1.000
C3—S4	1.818 (2)	C6—H61	1.000
H22—C2—H21	109.467	H52—C5—H51	109.466
H22—C2—C3	109.481	H52—C5—C6	108.313
H21—C2—C3	109.481	H51—C5—C6	108.313
H22—C2—Cl1	109.482	H52—C5—S4	108.313
H21—C2—Cl1	109.482	H51—C5—S4	108.314
C3—C2—Cl1	109.43 (12)	C6—C5—S4	114.06 (14)
H32—C3—H31	109.467	H63—C6—H62	109.476
H32—C3—S4	109.131	H63—C6—H61	109.475
H31—C3—S4	109.131	H62—C6—H61	109.476
H32—C3—C2	109.131	H63—C6—C5	109.466
H31—C3—C2	109.131	H62—C6—C5	109.467
S4—C3—C2	110.83 (12)	H61—C6—C5	109.467
C5—S4—C3	100.67 (10)
C5—S4—C3—C2	83.17 (14)	Cl1—C2—C3—S4	−177.38 (9)
C3—S4—C5—C6	73.81 (16)