2,6-Bis(4-meth-oxy-phen-yl)-1,4-dithiine.

The title mol-ecule, C18H16O2S2, reveals crystallographic twofold rotation symmetry (with both S atoms lying on the axis) and one half-mol-ecule defines an asymmetric unit. The dithiine ring is in a boat conformation. The aromatic ring and the C=C bond are nearly coplanar, with small torsion angles of -171.26 (19) and 8.5 (3)°. The two S-C bond lengths [1.7391 (19) and 1.7795 (18) Å] are shorter than single C-S bonds and longer than analogous C=S double bonds, which indicates a certain degree of conjugation between the lone pair on the S atom and π electrons of the C=C bond. The crystal packing only features van der Waals inter-actions.

Related literature

For a similar crystal structure, 2,6-diphenyl-1,4-dithiine, see: Piao et al. (2004 ▶). For background to 1,4-dithiine derivatives, see: Kobayashi & Gajurel (1986 ▶); Scott et al. (2000 ▶). For the synthesis of a similar compound, see: Nakayama et al. (1984 ▶). For standard bond lengths, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C18H16O2S2

M = 328.43

Orthorhombic,

a = 10.1330 (11) Å

b = 27.318 (3) Å

c = 5.5402 (6) Å

V = 1533.6 (3) Å3

Z = 4

Mo Kα radiation

μ = 0.35 mm−1

T = 293 K

0.21 × 0.18 × 0.09 mm

Data collection

Bruker SMART CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T min = 0.121, T max = 1.000

8513 measured reflections

1541 independent reflections

1258 reflections with I > 2σ(I)

R int = 0.043

Refinement

R[F 2 > 2σ(F 2)] = 0.038

wR(F 2) = 0.102

S = 1.04

1541 reflections

104 parameters

H-atom parameters constrained

Δρmax = 0.29 e Å−3

Δρmin = −0.16 e Å−3

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT (Bruker, 2001 ▶); data reduction: SAINT; 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: SHELXTL.

Crystal structure: contains datablock(s) I, New_Global_Publ_Block. DOI: 10.1107/S1600536814000397/kp2462sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814000397/kp2462Isup2.hkl

Click here for additional data file.

Supporting information file. DOI: 10.1107/S1600536814000397/kp2462Isup3.cml

CCDC reference:

Additional supporting information: crystallographic information; 3D view; checkCIF report

C18H16O2S2	F(000) = 688
Mr = 328.43	Dx = 1.422 Mg m−3
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	Cell parameters from 1658 reflections
a = 10.1330 (11) Å	θ = 7.5–53.8°
b = 27.318 (3) Å	µ = 0.35 mm−1
c = 5.5402 (6) Å	T = 293 K
V = 1533.6 (3) Å3	Prismatic, yellow
Z = 4	0.21 × 0.18 × 0.09 mm

Bruker SMART CCD area-detector diffractometer	1541 independent reflections
Radiation source: fine-focus sealed tube	1258 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.043
phi and ω scans	θmax = 26.0°, θmin = 3.0°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −12→12
Tmin = 0.121, Tmax = 1.000	k = −33→32
8513 measured reflections	l = −5→6

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.102	H-atom parameters constrained
S = 1.04	w = 1/[σ2(Fo2) + (0.0554P)2 + 0.3159P] where P = (Fo2 + 2Fc2)/3
1541 reflections	(Δ/σ)max < 0.001
104 parameters	Δρmax = 0.29 e Å−3
0 restraints	Δρmin = −0.16 e Å−3

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.

	x	y	z	Uiso*/Ueq
S1	0.49280 (7)	0.2500	0.16602 (12)	0.0352 (2)
S2	0.70856 (7)	0.2500	−0.24173 (15)	0.0423 (2)
O1	0.14361 (14)	0.45648 (5)	0.0468 (3)	0.0484 (4)
C1	0.60102 (19)	0.29896 (6)	−0.2021 (4)	0.0364 (5)
H1	0.6115	0.3262	−0.3011	0.044*
C2	0.50486 (19)	0.29989 (6)	−0.0393 (3)	0.0307 (4)
C3	0.40701 (18)	0.33990 (6)	−0.0143 (3)	0.0296 (4)
C4	0.3199 (2)	0.34206 (7)	0.1786 (4)	0.0364 (5)
H4	0.3213	0.3172	0.2931	0.044*
C5	0.2311 (2)	0.38017 (7)	0.2059 (3)	0.0372 (5)
H5	0.1746	0.3808	0.3381	0.045*
C6	0.22660 (19)	0.41714 (7)	0.0376 (3)	0.0352 (5)
C7	0.31115 (19)	0.41530 (7)	−0.1595 (4)	0.0395 (5)
H7	0.3083	0.4399	−0.2753	0.047*
C8	0.3984 (2)	0.37754 (7)	−0.1841 (4)	0.0371 (5)
H8	0.4537	0.3769	−0.3180	0.044*
C9	0.0549 (2)	0.45883 (8)	0.2462 (5)	0.0556 (6)
H9A	0.0005	0.4301	0.2479	0.083*
H9B	0.0002	0.4874	0.2311	0.083*
H9C	0.1043	0.4606	0.3938	0.083*

	U11	U22	U33	U12	U13	U23
S1	0.0430 (4)	0.0328 (4)	0.0297 (4)	0.000	−0.0017 (3)	0.000
S2	0.0266 (4)	0.0405 (4)	0.0599 (5)	0.000	0.0101 (3)	0.000
O1	0.0487 (9)	0.0401 (8)	0.0563 (10)	0.0129 (7)	0.0112 (7)	0.0073 (7)
C1	0.0326 (10)	0.0306 (9)	0.0459 (12)	−0.0035 (8)	0.0042 (9)	0.0016 (8)
C2	0.0304 (9)	0.0287 (9)	0.0332 (11)	−0.0063 (8)	−0.0021 (8)	−0.0015 (7)
C3	0.0290 (10)	0.0274 (9)	0.0324 (10)	−0.0058 (8)	−0.0013 (8)	−0.0028 (7)
C4	0.0416 (11)	0.0314 (9)	0.0361 (11)	−0.0007 (8)	0.0067 (8)	0.0043 (8)
C5	0.0397 (11)	0.0362 (10)	0.0357 (11)	0.0002 (9)	0.0093 (9)	0.0000 (8)
C6	0.0333 (10)	0.0305 (10)	0.0420 (11)	−0.0001 (8)	−0.0015 (9)	−0.0015 (8)
C7	0.0421 (11)	0.0382 (10)	0.0381 (11)	0.0000 (9)	0.0019 (9)	0.0095 (9)
C8	0.0383 (11)	0.0397 (10)	0.0331 (11)	0.0004 (9)	0.0062 (8)	0.0030 (8)
C9	0.0548 (14)	0.0493 (13)	0.0627 (15)	0.0180 (11)	0.0168 (12)	0.0019 (12)

S1—C2	1.7795 (18)	C4—C5	1.384 (3)
S1—C2i	1.7795 (18)	C4—H4	0.9300
S2—C1	1.7391 (19)	C5—C6	1.375 (3)
S2—C1i	1.7391 (19)	C5—H5	0.9300
O1—C6	1.365 (2)	C6—C7	1.389 (3)
O1—C9	1.426 (3)	C7—C8	1.365 (3)
C1—C2	1.328 (3)	C7—H7	0.9300
C1—H1	0.9300	C8—H8	0.9300
C2—C3	1.482 (3)	C9—H9A	0.9600
C3—C4	1.387 (3)	C9—H9B	0.9600
C3—C8	1.397 (3)	C9—H9C	0.9600
C2—S1—C2i	99.97 (12)	C4—C5—H5	120.0
C1—S2—C1i	100.54 (13)	O1—C6—C5	124.98 (18)
C6—O1—C9	116.92 (16)	O1—C6—C7	115.96 (17)
C2—C1—S2	124.07 (15)	C5—C6—C7	119.06 (18)
C2—C1—H1	118.0	C8—C7—C6	120.36 (18)
S2—C1—H1	118.0	C8—C7—H7	119.8
C1—C2—C3	124.65 (16)	C6—C7—H7	119.8
C1—C2—S1	118.03 (15)	C7—C8—C3	121.97 (18)
C3—C2—S1	117.32 (14)	C7—C8—H8	119.0
C4—C3—C8	116.60 (17)	C3—C8—H8	119.0
C4—C3—C2	121.94 (16)	O1—C9—H9A	109.5
C8—C3—C2	121.46 (16)	O1—C9—H9B	109.5
C5—C4—C3	121.98 (17)	H9A—C9—H9B	109.5
C5—C4—H4	119.0	O1—C9—H9C	109.5
C3—C4—H4	119.0	H9A—C9—H9C	109.5
C6—C5—C4	120.00 (18)	H9B—C9—H9C	109.5
C6—C5—H5	120.0
C1i—S2—C1—C2	39.0 (2)	C3—C4—C5—C6	0.6 (3)
S2—C1—C2—C3	−175.75 (14)	C9—O1—C6—C5	−0.4 (3)
S2—C1—C2—S1	4.9 (2)	C9—O1—C6—C7	179.31 (19)
C2i—S1—C2—C1	−48.1 (2)	C4—C5—C6—O1	−179.75 (18)
C2i—S1—C2—C3	132.49 (11)	C4—C5—C6—C7	0.6 (3)
C1—C2—C3—C4	−171.26 (19)	O1—C6—C7—C8	179.64 (18)
S1—C2—C3—C4	8.1 (2)	C5—C6—C7—C8	−0.7 (3)
C1—C2—C3—C8	8.5 (3)	C6—C7—C8—C3	−0.5 (3)
S1—C2—C3—C8	−172.18 (14)	C4—C3—C8—C7	1.6 (3)
C8—C3—C4—C5	−1.7 (3)	C2—C3—C8—C7	−178.16 (18)
C2—C3—C4—C5	178.07 (17)