6-Bromo-1,3-benzothiazol-2-amine

The r.m.s. deviation from the mean plane for the non-H atoms in the title compound, C7H5BrN2S, is 0.011 Å. In the crystal, the molecules are linked by N—H⋯N and N—H⋯Br hydrogen bonds to generate (010) sheets. Weak aromatic π–π stacking [centroid-to-centroid separation = 3.884 (10) Å] and possible C—H⋯Br interactions are also observed. The crystal studied was found to be an inversion twin.

The single crystals of the title compound ( Fig.1) with the formula C 7 H 5 BrN 2 S was obtained by slow evaporating its methanol solution.
The 6-bromobenzo[d]thiazol-2-amine molecules ( Fig. 1) are linked together in head to tail fashion via the N-H···Br association to form one-dimensional chain running along the direction that made a dihedral angle of ca 30° with the a axis direction. Two neighboring chains were held together by the CH-Br interaction with C-Br distance of 3.402 Å generating one-dimensional double chain (Fig.2). The double chains were stacked along the direction that is perpendicular with its extending direction by the CH-Br interaction with C-Br distance of 3.402 Å to form twodimensional sheet extending parallel to the ac plane. The sheets were further stacked along the b axis direction by the intersheet N-H···N hydrogen bonds to form three-dimensional ABAB layer network structure.

Experimental
The 6-bromobenzo[d]thiazol-2-amine (22.9 mg, 0.1 mmol) was dissolved in a methanol solution (8 ml). The solution was filtered into a test tube. The solution was left standing at room temperature for a month, light-yellow blocks were isolated after slow evaporation of the methanol solution to ca 3 ml in air.

Refinement
H atoms bonded N atoms were located in a6-Bromo-1,3-benzothiazol-2-amine difference Fourier map and refined isotropically. Other H atoms were positioned geometrically with C-H = 0.93 Å, and constrained to ride on their parent atoms with U iso (H) = 1.2Ueq(C).

Figure 2
One-dimensional double chain structure.

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 F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.