2,2'-(1,2-Ethanediyldithio)bis(1,3-benzothiazole)

In the title compound, C₁₆H₁₂N₂S₄, which is the result of the S-alkyl­ation reaction of 2-mercapto­benzo­thia­zole with ethyl­ene dibromide, the planes of the two benzo­thia­zole moieties form a dihedral angle of 3.84 (14)°. The bridging chain moiety, -SCH₂CH₂S-, adopts an antiperiplanar conformation. There are intermolecular S...S non-bonded contacts of 3.6471 (9) Å, which stabilize the crystal packing.

S1. Comment

Acyclic crown ethers with N-heterocycle end-groups that will coordinate and transport metals have been of interest for several years (Vo¨gtle & Weber, 1979; Meth-Cohn & Smith, 1982; Liu et al., 1992; Matthews et al., 1996). Bis(benzothiazole) compounds have been studied as potential mimics for metalloproteins (Thompson et al., 1982) and bleomycin (Kane et al., 1995). We have recently reported the synthesis and characterization of bis(benzothiazole) acyclic crown ethers (Liu et al., 2001). We report here the X-ray crystal structure of the title compound, (I). \sch

In the molecular structure of (I) (Fig. 1), the two benzothiazole moieties make a dihedral angle of 3.84 (14)°, in nearly the same plane. The two thiazole moieties, like those of bis(benzothiazole-2-ylsulfanyl)methane (Matthews et al., 1996) and bis(2-benzothiazolyl)disulfane (Zingaro & Meyers, 1980), are anti to each other. The bridging chain moiety, SCH₂CH₂S, adopts an antiperiplanar conformation. The whole molecule possesses a local centre of symmetry. The bond lengths and angles in (I) show normal values (Table 1).

The crystal packing of (I) is shown in Fig. 2. As seen in bis(benzothiazole-2-ylsulfanyl)methane (Matthews et al., 1996) and bis(2-benzothiazolyl)disulfane (Zingaro & Meyers, 1980), there are intermolecular S1···S4(1/2 + x, 1/2 − y, z − 1/2) non-bonded contacts of 3.6471 (9) Å. These S···S contacts and cross-linking interactions stabilize the crystal packing.

S2. Experimental

The title compound was prepared via the S-alkylation reaction of 2-mercaptobenzothiazole with ethylene dibromide in acetone solution using potassium carbonate as base. Single crystals of (I) (m.p. 422–423 K) suitable for X-ray diffraction were obtained by slow evaporation of an acetone solution.

S3. Refinement

The positions of all H atoms were fixed geometrically, with C—H distances in the range 0.93–0.97 Å. Is this altered text OK?

Computing details

Data collection: XSCANS (Siemens, 1994); cell refinement: XSCANS; data reduction: SHELXTL (Sheldrick, 1997); program(s) used to solve structure: SHELXTL; program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The molecular structure of (I), showing 50% probability displacement ellipsoids and the atom-numbering scheme. H atoms are shown as small spheres of arbitrary radii.
	Fig. 2. The molecular packing diagram for the crystal of (I).

2,2'-(1,2-Ethanediyldithio)bis(1,3-benzothiazole)

Crystal data

C16H12N2S4	F(000) = 744
Mr = 360.52	Dx = 1.520 Mg m^−3
Monoclinic, P21/n	Melting point = 422–423 K
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71073 Å
a = 11.513 (2) Å	Cell parameters from 29 reflections
b = 10.711 (2) Å	θ = 2.7–14.8°
c = 13.998 (2) Å	µ = 0.60 mm^−1
β = 114.10 (1)°	T = 296 K
V = 1575.7 (5) Å^3	Plate, colourless
Z = 4	0.48 × 0.44 × 0.40 mm

Data collection

Siemens P4 diffractometer	2095 reflections with I > 2σ(I)
Radiation source: normal-focus sealed tube	Rint = 0.010
Graphite monochromator	θmax = 25.0°, θmin = 1.9°
ω scans	h = 0→13
Absorption correction: empirical (using intensity measurements) (SHELXS86; Sheldrick, 1990)	k = 0→12
Tmin = 0.748, Tmax = 0.787	l = −16→15
3203 measured reflections	3 standard reflections every 97 reflections
2779 independent reflections	intensity decay: 6.4%

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)] = 0.030	H-atom parameters constrained
wR(F^2) = 0.080	w = 1/[σ^2(Fo^2) + (0.0419P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.06	(Δ/σ)max = 0.001
2779 reflections	Δρmax = 0.25 e Å^−3
200 parameters	Δρmin = −0.19 e Å^−3
0 restraints	Extinction correction: SHELXTL (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0095 (9)

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. The structure was solved by direct methods (Sheldrick, 1990) and successive difference Fourier syntheses. 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	0.21696 (5)	0.46192 (5)	0.11324 (4)	0.04871 (17)
S2	0.23804 (5)	0.59668 (6)	0.30564 (5)	0.05732 (19)
S3	−0.06760 (6)	0.66361 (6)	0.41449 (5)	0.05797 (19)
S4	−0.06197 (5)	0.80194 (6)	0.59981 (5)	0.05468 (19)
N1	0.05754 (15)	0.42452 (15)	0.19951 (12)	0.0430 (4)
N2	0.11139 (16)	0.83470 (15)	0.52787 (13)	0.0444 (4)
C1	0.02168 (18)	0.34570 (18)	0.11272 (15)	0.0388 (5)
C2	−0.0795 (2)	0.2617 (2)	0.08144 (18)	0.0506 (6)
H2	−0.1302	0.2549	0.1187	0.061*
C3	−0.1032 (2)	0.1890 (2)	−0.00576 (19)	0.0589 (6)
H3	−0.1702	0.1324	−0.0269	0.071*
C4	−0.0293 (2)	0.1983 (2)	−0.06268 (18)	0.0592 (6)
H4	−0.0480	0.1485	−0.1215	0.071*
C5	0.0715 (2)	0.2805 (2)	−0.03308 (16)	0.0495 (5)
H5	0.1212	0.2868	−0.0711	0.059*
C6	0.09675 (18)	0.35346 (18)	0.05516 (15)	0.0386 (5)
C7	0.15677 (18)	0.48878 (19)	0.20800 (16)	0.0417 (5)
C8	0.1441 (2)	0.5911 (2)	0.38309 (16)	0.0566 (6)
H8A	0.1181	0.5057	0.3862	0.068*
H8B	0.1964	0.6179	0.4539	0.068*
C9	0.0287 (2)	0.6722 (2)	0.33877 (16)	0.0547 (6)
H9A	−0.0225	0.6468	0.2673	0.066*
H9B	0.0549	0.7580	0.3373	0.066*
C10	0.0090 (2)	0.77261 (19)	0.51278 (16)	0.0432 (5)
C11	0.14153 (18)	0.91434 (18)	0.61384 (15)	0.0398 (5)
C12	0.2446 (2)	0.9947 (2)	0.65147 (17)	0.0496 (5)
H12	0.3005	0.9996	0.6189	0.060*
C13	0.2634 (2)	1.0674 (2)	0.73778 (18)	0.0560 (6)
H13	0.3325	1.1216	0.7635	0.067*
C14	0.1802 (2)	1.0607 (2)	0.78669 (17)	0.0569 (6)
H14	0.1947	1.1102	0.8450	0.068*
C15	0.0768 (2)	0.9822 (2)	0.75050 (17)	0.0548 (6)
H15	0.0212	0.9784	0.7834	0.066*
C16	0.05743 (19)	0.90868 (19)	0.66356 (16)	0.0430 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0474 (3)	0.0522 (4)	0.0528 (3)	−0.0096 (3)	0.0269 (3)	−0.0046 (3)
S2	0.0502 (4)	0.0621 (4)	0.0574 (4)	−0.0109 (3)	0.0197 (3)	−0.0186 (3)
S3	0.0519 (4)	0.0547 (4)	0.0668 (4)	−0.0077 (3)	0.0236 (3)	−0.0130 (3)
S4	0.0457 (3)	0.0605 (4)	0.0677 (4)	−0.0013 (3)	0.0331 (3)	−0.0034 (3)
N1	0.0413 (10)	0.0439 (10)	0.0464 (10)	−0.0024 (8)	0.0206 (8)	−0.0053 (8)
N2	0.0450 (10)	0.0451 (10)	0.0465 (10)	−0.0005 (8)	0.0223 (8)	−0.0015 (8)
C1	0.0373 (11)	0.0336 (11)	0.0458 (11)	0.0023 (9)	0.0173 (9)	−0.0003 (9)
C2	0.0468 (13)	0.0466 (13)	0.0656 (15)	−0.0045 (10)	0.0302 (12)	−0.0049 (11)
C3	0.0507 (14)	0.0472 (14)	0.0767 (16)	−0.0107 (11)	0.0238 (13)	−0.0160 (12)
C4	0.0628 (15)	0.0534 (14)	0.0566 (14)	−0.0009 (12)	0.0196 (13)	−0.0172 (12)
C5	0.0564 (14)	0.0499 (13)	0.0469 (12)	0.0027 (11)	0.0258 (11)	−0.0029 (11)
C6	0.0391 (11)	0.0357 (11)	0.0410 (11)	0.0026 (9)	0.0165 (9)	0.0029 (9)
C7	0.0390 (11)	0.0419 (12)	0.0429 (11)	0.0021 (10)	0.0153 (9)	−0.0020 (9)
C8	0.0598 (15)	0.0596 (15)	0.0442 (12)	0.0057 (12)	0.0151 (11)	−0.0050 (11)
C9	0.0601 (14)	0.0497 (13)	0.0440 (12)	0.0042 (11)	0.0110 (11)	−0.0024 (10)
C10	0.0427 (12)	0.0413 (12)	0.0466 (12)	0.0081 (10)	0.0191 (10)	0.0043 (10)
C11	0.0385 (11)	0.0402 (11)	0.0411 (11)	0.0069 (9)	0.0167 (9)	0.0027 (9)
C12	0.0502 (13)	0.0509 (13)	0.0517 (13)	−0.0045 (11)	0.0248 (11)	−0.0006 (11)
C13	0.0564 (14)	0.0500 (14)	0.0545 (14)	−0.0043 (12)	0.0154 (12)	−0.0044 (12)
C14	0.0678 (16)	0.0539 (14)	0.0452 (13)	0.0129 (13)	0.0192 (12)	−0.0064 (11)
C15	0.0597 (15)	0.0598 (15)	0.0525 (14)	0.0151 (12)	0.0307 (12)	0.0027 (12)
C16	0.0427 (11)	0.0430 (12)	0.0473 (12)	0.0096 (10)	0.0226 (10)	0.0046 (10)

Geometric parameters (Å, º)

S1—C6	1.734 (2)	C4—H4	0.9300
S1—C7	1.753 (2)	C5—C6	1.389 (3)
S2—C7	1.742 (2)	C5—H5	0.9300
S2—C8	1.818 (2)	C8—C9	1.494 (3)
S3—C10	1.744 (2)	C8—H8A	0.9700
S3—C9	1.822 (2)	C8—H8B	0.9700
S4—C16	1.730 (2)	C9—H9A	0.9700
S4—C10	1.750 (2)	C9—H9B	0.9700
N1—C7	1.297 (2)	C11—C12	1.384 (3)
N1—C1	1.396 (2)	C11—C16	1.406 (3)
N2—C10	1.294 (3)	C12—C13	1.378 (3)
N2—C11	1.398 (2)	C12—H12	0.9300
C1—C2	1.393 (3)	C13—C14	1.388 (3)
C1—C6	1.404 (3)	C13—H13	0.9300
C2—C3	1.378 (3)	C14—C15	1.374 (3)
C2—H2	0.9300	C14—H14	0.9300
C3—C4	1.386 (3)	C15—C16	1.389 (3)
C3—H3	0.9300	C15—H15	0.9300
C4—C5	1.379 (3)
C6—S1—C7	88.76 (9)	C9—C8—H8B	109.2
C7—S2—C8	100.75 (10)	S2—C8—H8B	109.2
C10—S3—C9	101.14 (10)	H8A—C8—H8B	107.9
C16—S4—C10	88.81 (10)	C8—C9—S3	112.23 (15)
C7—N1—C1	109.70 (16)	C8—C9—H9A	109.2
C10—N2—C11	110.09 (17)	S3—C9—H9A	109.2
C2—C1—N1	125.16 (18)	C8—C9—H9B	109.2
C2—C1—C6	119.31 (18)	S3—C9—H9B	109.2
N1—C1—C6	115.53 (17)	H9A—C9—H9B	107.9
C3—C2—C1	118.7 (2)	N2—C10—S3	127.33 (16)
C3—C2—H2	120.6	N2—C10—S4	116.57 (16)
C1—C2—H2	120.6	S3—C10—S4	116.10 (12)
C2—C3—C4	121.5 (2)	C12—C11—N2	125.44 (18)
C2—C3—H3	119.2	C12—C11—C16	119.68 (19)
C4—C3—H3	119.2	N2—C11—C16	114.89 (18)
C5—C4—C3	120.8 (2)	C13—C12—C11	119.2 (2)
C5—C4—H4	119.6	C13—C12—H12	120.4
C3—C4—H4	119.6	C11—C12—H12	120.4
C4—C5—C6	118.1 (2)	C12—C13—C14	120.6 (2)
C4—C5—H5	120.9	C12—C13—H13	119.7
C6—C5—H5	120.9	C14—C13—H13	119.7
C5—C6—C1	121.53 (19)	C15—C14—C13	121.2 (2)
C5—C6—S1	129.13 (16)	C15—C14—H14	119.4
C1—C6—S1	109.33 (14)	C13—C14—H14	119.4
N1—C7—S2	126.49 (16)	C14—C15—C16	118.4 (2)
N1—C7—S1	116.69 (15)	C14—C15—H15	120.8
S2—C7—S1	116.81 (11)	C16—C15—H15	120.8
C9—C8—S2	112.22 (16)	C15—C16—C11	120.8 (2)
C9—C8—H8A	109.2	C15—C16—S4	129.52 (17)
S2—C8—H8A	109.2	C11—C16—S4	109.64 (15)
C7—N1—C1—C2	178.7 (2)	C10—S3—C9—C8	84.38 (17)
C7—N1—C1—C6	−0.6 (2)	C11—N2—C10—S3	179.06 (15)
N1—C1—C2—C3	−179.52 (19)	C11—N2—C10—S4	−0.3 (2)
C6—C1—C2—C3	−0.3 (3)	C9—S3—C10—N2	−3.7 (2)
C1—C2—C3—C4	−0.4 (3)	C9—S3—C10—S4	175.63 (12)
C2—C3—C4—C5	0.6 (4)	C16—S4—C10—N2	0.03 (17)
C3—C4—C5—C6	0.0 (3)	C16—S4—C10—S3	−179.41 (12)
C4—C5—C6—C1	−0.7 (3)	C10—N2—C11—C12	−179.6 (2)
C4—C5—C6—S1	178.61 (17)	C10—N2—C11—C16	0.5 (2)
C2—C1—C6—C5	0.8 (3)	N2—C11—C12—C13	−179.47 (19)
N1—C1—C6—C5	−179.88 (18)	C16—C11—C12—C13	0.4 (3)
C2—C1—C6—S1	−178.58 (16)	C11—C12—C13—C14	−0.1 (3)
N1—C1—C6—S1	0.7 (2)	C12—C13—C14—C15	−0.3 (3)
C7—S1—C6—C5	−179.8 (2)	C13—C14—C15—C16	0.3 (3)
C7—S1—C6—C1	−0.51 (15)	C14—C15—C16—C11	0.1 (3)
C1—N1—C7—S2	−178.44 (15)	C14—C15—C16—S4	−179.99 (16)
C1—N1—C7—S1	0.1 (2)	C12—C11—C16—C15	−0.4 (3)
C8—S2—C7—N1	−0.8 (2)	N2—C11—C16—C15	179.48 (18)
C8—S2—C7—S1	−179.38 (12)	C12—C11—C16—S4	179.62 (16)
C6—S1—C7—N1	0.22 (17)	N2—C11—C16—S4	−0.5 (2)
C6—S1—C7—S2	178.95 (13)	C10—S4—C16—C15	−179.7 (2)
C7—S2—C8—C9	−82.90 (18)	C10—S4—C16—C11	0.25 (15)
S2—C8—C9—S3	178.53 (11)