5-Phenyl-1,2,5-di­thia­zepane

In the title compound, C₁₀H₁₃NS₂, the seven-membered ring adopts a chair conformation. The S—S bond length is 2.0406 (5) Å and the C—S—S—C torsion angle is −83.89 (7)°. The amine group is sp²-hybridized. In the crystal, mol­ecules are linked into chains along [001] by weak inter­molecular S...S contacts of 3.5246 (5) Å.

Key indicators

• Single-crystal X-ray study
• T = 153 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.024
• wR factor = 0.064
• Data-to-parameter ratio = 14.9

checkCIF/PLATON results

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Alert level C
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          7 Why ?
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.595         13
PLAT913_ALERT_3_C Missing # of Very Strong Reflections in FCF ....          3

Alert level G
PLAT005_ALERT_5_G No _iucr_refine_instructions_details  in the CIF     Please Do !
PLAT128_ALERT_4_G Alternate Setting for Input Space-Group  P21/c        P21/n Note
PLAT909_ALERT_3_G Percentage of Observed Data at Theta(Max) still          93 %

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   3 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   3 ALERT level G = General information/check it is not something unexpected

   0 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
   4 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

Cyclic disulfides are of special interest because they are often a key component in many biologically relevant peptides (Pazderlová et al., 2012). Because of this disulfide compounds are regularly found to have pharmacological activities. Herein is described the crystallographic properties of a 7-membered cyclic disulfide compound. The molecular structure of the title compound can be seen in Fig. 1.

The S—S bond distance is 2.0406 (5) Å. This value is comparable to other disulfide compounds. The mean average bond length for C—S—S—C bonds from 99 samples, reported by (Allen et al., 1987) is 2.048 Å. The torsion in the C—S—S—C bonds is -83.89 (7)°, this compares similarly to the C—S—S—C torsion in the 7-membered ring disulfide 1,2,4,6-tetrathiacycloheptane reported in (Pickardt et al., 2006), which has a C—S—S—C torsion of -89.4 (2)°.

The seven-membered ring adopts a chair conformation, as it does in the cyclic disulfide compound reported by Pickardt et al. (2006). The dominant intermolecular interactions are between S1···S2 of symmetry-related molecules. The contacts have a distance of 3.5246 (5) Å, this compares similarly to S···S interactions observed perviously by Chen et al. (2009) and Reinheimer et al. (2009) which are 3.396 (1) - 3.470 (1) Å and 3.580 (4) Å respectively.

The pyramidality of the amine functionality, measured by χn, the angle between the C1—N1 vector and the N1/C7/C9 plane, described by Allen et al. (1995), is 7.26 (15)°, indicating that the hybridization of the nitrogen atoms is mainly sp² (sp² χ_n ≈ 0°, sp³ χ_n ≈ 60°).

Related literature

For properties of disulfide compounds, see: Pazderlová et al. (2012). For similar compounds, see: Roze et al. (2006); Bulavin (1971). For related structures, see: Pickardt et al. (2006); Capasso et al. (1977). For standard bond lengths, see: Allen et al. (1987). For previous reports of S···S interactions, see: Chen et al. (2009); Reinheimer et al. (2009). For the calculation of the functionality of the amine group in terms of hybridization, see: Allen et al. (1995). For the synthesis, see: Elderfield et al. (1958).

S2. Experimental

The title compound was prepared from N,N-bis(2-chloroethyl)aniline which had been prepared following literature methods reported by Elderfield et al. (1958). NaSH·H₂O (1.08 g, 14.78 mmol) was stirred in ethanol (20 ml) under an argon atmosphere for 1 hr. N,N-bis(2-chloroethyl)aniline (0.5124 g, 2.35 mmol) was dissolved in ethanol (10 ml) under argon and then transferred into the NaSH·H₂O solution via cannula. The reaction mixture was then heated to reflux for 24 hrs. The solvent volume was reduced by half in vacuo before degassed CH₂Cl₂ and H₂O were added to the reaction flask and the product was extracted under argon. The organic phase was then transferred via cannula into a flask containing MgSO₄. The product was isolated by filtration and removal of the solvent under vacuum. The X-ray quality crystals were obtained from a saturated dichloromethane solution of the title compound upon standing at 263 K for several days. Yield = 83%. ¹H NMR (300 MHz, CDCl₃): δ 7.25 (m, 2H), 6.85 (m, 3H), 3.52 (m, 4H), 2.74 (m, 4H).

S3. Refinement

All H atoms were positioned geometrically and refined using a riding model, with C—H = 0.93–0.97 Å and with U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: COLLECT (Nonius, 1998); cell refinement: COLLECT (Nonius, 1998); data reduction: DENZO and SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR97 (Altomare et al., 1999) within WinGX (Farrugia, 2012); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and publCIF (Westrip, 2010).

Figures

	Fig. 1. Molecular structure of title compound. Ellipsoids are drawn at the 50% probability level.
	Fig. 2. Part of the crystal structure viewed along the a axis. Interactions are shown between S1 and S2 of molecules related by the crystallographic c-glide.

5-Phenyl-1,2,5-dithiazepane

Crystal data

C10H13NS2	F(000) = 448
Mr = 211.33	Dx = 1.392 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71070 Å
Hall symbol: -P 2ybc	Cell parameters from 1974 reflections
a = 9.5760 (2) Å	θ = 1.0–27.5°
b = 12.2310 (3) Å	µ = 0.48 mm^−1
c = 9.9811 (2) Å	T = 153 K
β = 120.392 (2)°	Block, white
V = 1008.38 (4) Å^3	0.50 × 0.30 × 0.20 mm
Z = 4

Data collection

Nonius Kappa CCD diffractometer	1763 independent reflections
Radiation source: fine-focus sealed tube	1675 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.012
ω scans	θmax = 25.0°, θmin = 4.1°
Absorption correction: multi-scan (DENZO and SCALEPACK; Otwinowski & Minor, 1997)	h = −11→11
Tmin = 0.856, Tmax = 1	k = −12→14
3055 measured reflections	l = −11→11

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)] = 0.024	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.064	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0266P)^2 + 0.5691P] where P = (Fo^2 + 2Fc^2)/3
1763 reflections	(Δ/σ)max = 0.002
118 parameters	Δρmax = 0.25 e Å^−3
0 restraints	Δρmin = −0.21 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 > 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
S1	1.04272 (4)	0.28440 (3)	0.62971 (4)	0.02268 (12)
S2	1.07376 (4)	0.34787 (3)	0.83210 (4)	0.02409 (12)
N1	0.74239 (13)	0.43703 (9)	0.57782 (13)	0.0190 (3)
C1	0.65295 (16)	0.42454 (11)	0.65031 (15)	0.0187 (3)
C2	0.66903 (17)	0.49796 (12)	0.76593 (16)	0.0218 (3)
H2	0.7434	0.5548	0.7965	0.026*
C3	0.57560 (17)	0.48654 (13)	0.83458 (16)	0.0261 (3)
H3	0.5882	0.5360	0.9107	0.031*
C4	0.46349 (18)	0.40283 (13)	0.79229 (17)	0.0282 (3)
H4	0.4006	0.3960	0.8386	0.034*
C5	0.44731 (17)	0.32959 (13)	0.67931 (17)	0.0261 (3)
H5	0.3723	0.2732	0.6495	0.031*
C6	0.54029 (17)	0.33875 (12)	0.61020 (16)	0.0223 (3)
H6	0.5285	0.2877	0.5362	0.027*
C7	0.72559 (17)	0.36111 (11)	0.45867 (16)	0.0217 (3)
H7A	0.7562	0.3982	0.3915	0.026*
H7B	0.6125	0.3407	0.3958	0.026*
C8	0.82641 (17)	0.25754 (11)	0.52070 (17)	0.0224 (3)
H8A	0.8026	0.2096	0.4342	0.027*
H8B	0.7956	0.2197	0.5873	0.027*
C9	0.87194 (17)	0.51649 (11)	0.63274 (17)	0.0231 (3)
H9A	0.8296	0.5868	0.6406	0.028*
H9B	0.9037	0.5236	0.5550	0.028*
C10	1.02434 (18)	0.49172 (12)	0.78971 (17)	0.0259 (3)
H10A	1.0103	0.5229	0.8715	0.031*
H10B	1.1157	0.5283	0.7926	0.031*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0207 (2)	0.0222 (2)	0.0268 (2)	0.00209 (13)	0.01317 (16)	0.00058 (13)
S2	0.0215 (2)	0.0287 (2)	0.0192 (2)	−0.00065 (14)	0.00822 (15)	0.00285 (13)
N1	0.0195 (6)	0.0174 (6)	0.0198 (6)	−0.0004 (4)	0.0097 (5)	−0.0012 (4)
C1	0.0171 (7)	0.0180 (7)	0.0177 (6)	0.0048 (5)	0.0062 (5)	0.0045 (5)
C2	0.0202 (7)	0.0199 (7)	0.0222 (7)	0.0019 (5)	0.0085 (6)	0.0003 (5)
C3	0.0253 (7)	0.0307 (8)	0.0217 (7)	0.0072 (6)	0.0115 (6)	0.0004 (6)
C4	0.0225 (7)	0.0376 (8)	0.0274 (7)	0.0064 (6)	0.0148 (6)	0.0083 (7)
C5	0.0178 (7)	0.0270 (8)	0.0296 (8)	0.0004 (6)	0.0090 (6)	0.0063 (6)
C6	0.0196 (7)	0.0209 (7)	0.0219 (7)	0.0010 (5)	0.0072 (6)	0.0000 (5)
C7	0.0223 (7)	0.0235 (7)	0.0180 (7)	0.0018 (6)	0.0091 (6)	−0.0007 (5)
C8	0.0215 (7)	0.0206 (7)	0.0242 (7)	−0.0005 (6)	0.0109 (6)	−0.0044 (6)
C9	0.0280 (7)	0.0183 (7)	0.0275 (7)	−0.0024 (6)	0.0173 (6)	0.0002 (6)
C10	0.0241 (7)	0.0238 (7)	0.0291 (8)	−0.0048 (6)	0.0130 (6)	−0.0069 (6)

Geometric parameters (Å, º)

S1—C8	1.8171 (14)	C5—C6	1.379 (2)
S1—S2	2.0406 (5)	C5—H5	0.9300
S2—C10	1.8155 (15)	C6—H6	0.9300
N1—C1	1.3811 (18)	C7—C8	1.5216 (19)
N1—C7	1.4523 (18)	C7—H7A	0.9700
N1—C9	1.4478 (18)	C7—H7B	0.9700
C1—C2	1.408 (2)	C8—H8A	0.9700
C1—C6	1.410 (2)	C8—H8B	0.9700
C2—C3	1.382 (2)	C9—C10	1.537 (2)
C2—H2	0.9300	C9—H9A	0.9700
C3—C4	1.386 (2)	C9—H9B	0.9700
C3—H3	0.9300	C10—H10A	0.9700
C4—C5	1.386 (2)	C10—H10B	0.9700
C4—H4	0.9300
C8—S1—S2	102.27 (5)	N1—C7—H7A	108.6
C10—S2—S1	104.34 (5)	C8—C7—H7A	108.6
C1—N1—C7	121.14 (11)	N1—C7—H7B	108.6
C1—N1—C9	121.04 (11)	C8—C7—H7B	108.6
C7—N1—C9	117.26 (11)	H7A—C7—H7B	107.6
N1—C1—C2	121.28 (12)	C7—C8—S1	112.92 (10)
N1—C1—C6	121.45 (12)	C7—C8—H8A	109.0
C2—C1—C6	117.26 (13)	S1—C8—H8A	109.0
C3—C2—C1	120.81 (14)	C7—C8—H8B	109.0
C3—C2—H2	119.6	S1—C8—H8B	109.0
C1—C2—H2	119.6	H8A—C8—H8B	107.8
C2—C3—C4	121.32 (14)	N1—C9—C10	116.32 (11)
C2—C3—H3	119.3	N1—C9—H9A	108.2
C4—C3—H3	119.3	C10—C9—H9A	108.2
C5—C4—C3	118.41 (14)	N1—C9—H9B	108.2
C5—C4—H4	120.8	C10—C9—H9B	108.2
C3—C4—H4	120.8	H9A—C9—H9B	107.4
C6—C5—C4	121.30 (14)	C9—C10—S2	115.45 (10)
C6—C5—H5	119.3	C9—C10—H10A	108.4
C4—C5—H5	119.3	S2—C10—H10A	108.4
C5—C6—C1	120.88 (14)	C9—C10—H10B	108.4
C5—C6—H6	119.6	S2—C10—H10B	108.4
C1—C6—H6	119.6	H10A—C10—H10B	107.5
N1—C7—C8	114.49 (11)
C8—S1—S2—C10	−83.89 (7)	N1—C1—C6—C5	−177.53 (12)
C7—N1—C1—C2	179.96 (12)	C2—C1—C6—C5	1.6 (2)
C9—N1—C1—C2	8.78 (19)	C1—N1—C7—C8	−83.69 (15)
C7—N1—C1—C6	−0.92 (19)	C9—N1—C7—C8	87.82 (15)
C9—N1—C1—C6	−172.10 (12)	N1—C7—C8—S1	−62.44 (14)
N1—C1—C2—C3	178.13 (12)	S2—S1—C8—C7	73.74 (10)
C6—C1—C2—C3	−1.0 (2)	C1—N1—C9—C10	69.91 (16)
C1—C2—C3—C4	0.0 (2)	C7—N1—C9—C10	−101.60 (14)
C2—C3—C4—C5	0.4 (2)	N1—C9—C10—S2	32.78 (16)
C3—C4—C5—C6	0.2 (2)	S1—S2—C10—C9	44.11 (12)
C4—C5—C6—C1	−1.3 (2)