2,2'-Di­amino-4,4'-bi-1,3-thia­zole

The centrosymmetric mol­ecule of the title compound, C₆H₆N₄S₂ (DABT), displays a trans planar configuration, except that the amino groups are inclined slightly to the bi­thia­zole plane. The N-C bond distance of 1.309 (2) Å within the thiazole ring is shorter than in DABT chloride [1.335 (6) Å] and in a DABT-metal complex [1.322 (3) Å]. The separation of 3.717 (3) Å between parallel bi­thia­zole rings of neighboring mol­ecules indicates a normal van der Waals contact.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.033
• wR factor = 0.084
• Data-to-parameter ratio = 16.0

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



PLAT_420  Alert C D-H Without Acceptor       N(6)   -   H(62)             ?


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 1 Alert Level C = Please check

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Computing details

Data collection: SMART (Bruker, 1999b); cell refinement: SAINT (Bruker, 1999c); data reduction: SAINT; program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

(I)

Crystal data

C6H6N4S2	F(000) = 204
Mr = 198.27	Dx = 1.702 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 2358 reflections
a = 5.151 (2) Å	θ = 4.3–27.2°
b = 11.468 (3) Å	µ = 0.63 mm^−1
c = 6.555 (3) Å	T = 150 K
β = 92.71 (1)°	Prism, colorless
V = 386.8 (3) Å^3	0.25 × 0.20 × 0.16 mm
Z = 2

Data collection

Bruker SMART CCD diffractometer	881 independent reflections
Radiation source: fine-focus sealed tube	792 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.036
ω and φ scans	θmax = 27.5°, θmin = 3.6°
Absorption correction: multi-scan (SADABS; Bruker, 1999a)	h = −6→6
Tmin = 0.855, Tmax = 0.904	k = −14→14
2404 measured reflections	l = −8→7

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)] = 0.033	Hydrogen site location: difference Fourier map
wR(F^2) = 0.084	H-atom parameters constrained
S = 1.10	w = 1/[σ^2(Fo^2) + (0.0471P)^2 + 0.1354P] where P = (Fo^2 + 2Fc^2)/3
881 reflections	(Δ/σ)max = 0.003
55 parameters	Δρmax = 0.40 e Å^−3
0 restraints	Δρmin = −0.31 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 > 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	0.27819 (8)	0.10448 (3)	0.41566 (6)	0.02020 (17)
N3	−0.1168 (3)	0.12321 (11)	0.1585 (2)	0.0156 (3)
N6	−0.1100 (3)	0.26059 (13)	0.4276 (2)	0.0234 (3)
C2	−0.0113 (3)	0.16953 (13)	0.3250 (2)	0.0159 (3)
C4	0.0373 (3)	0.03097 (12)	0.0944 (2)	0.0144 (3)
C5	0.2551 (3)	0.00871 (14)	0.2126 (2)	0.0182 (3)
H5	0.3855	−0.0477	0.1836	0.080*
H61	−0.0099	0.2985	0.5187	0.080*
H62	−0.2592	0.2806	0.3988	0.080*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0200 (3)	0.0222 (3)	0.0179 (3)	0.00299 (14)	−0.00489 (16)	−0.00418 (14)
N3	0.0155 (6)	0.0136 (6)	0.0177 (6)	−0.0001 (5)	0.0005 (5)	−0.0010 (5)
N6	0.0209 (7)	0.0206 (7)	0.0286 (8)	0.0016 (5)	0.0012 (6)	−0.0097 (6)
C2	0.0149 (7)	0.0145 (7)	0.0185 (7)	−0.0012 (6)	0.0016 (6)	0.0007 (5)
C4	0.0155 (7)	0.0121 (7)	0.0158 (7)	−0.0011 (5)	0.0016 (5)	0.0016 (5)
C5	0.0198 (8)	0.0169 (7)	0.0177 (7)	0.0018 (6)	−0.0016 (6)	−0.0018 (6)

Geometric parameters (Å, º)

S1—C5	1.7255 (17)	N6—H61	0.884
S1—C2	1.7461 (17)	N6—H62	0.816
N3—C2	1.309 (2)	C4—C5	1.358 (2)
N3—C4	1.3988 (19)	C4—C4^i	1.462 (3)
N6—C2	1.354 (2)	C5—H5	0.958
C5—S1—C2	89.02 (7)	N6—C2—S1	119.69 (12)
C2—N3—C4	109.78 (13)	C5—C4—N3	115.85 (14)
C2—N6—H61	119.6	C5—C4—C4^i	124.66 (17)
C2—N6—H62	118.3	N3—C4—C4^i	119.44 (16)
H61—N6—H62	122.1	C4—C5—S1	110.23 (12)
N3—C2—N6	125.18 (14)	C4—C5—H5	125.6
N3—C2—S1	115.13 (12)	S1—C5—H5	124.0

Symmetry code: (i) −x, −y, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N6—H61···N3^ii	0.885	2.360	3.187 (3)	156

Symmetry code: (ii) x+1/2, −y+1/2, z+1/2.