1-(5-Bromo-2-oxoindolin-3-ylidene)-4-phenylthiosemicarbazide

In the title compound, C15H11BrN4OS, the least-squares plane through the 5-bromoisatin fragment forms a dihedral angle of 13.63 (14)° with the phenyl ring. The molecular conformation features intramolecular N—H⋯N and N—H⋯O hydrogen bonds. In the crystal, molecules are connected via pairs of N—H⋯O interactions into centrosymmetric dimers. Additionally, π–π stacking interactions link molecules into chains parallel to the a axis with short C⋯C distances being observed between the phenyl and thiocarbonyl [3.236 (8) Å] groups and between the thiocarbonyl and carbonyl [3.351 (4) Å] groups of stacked molecules.

In the title compound, C 15 H 11 BrN 4 OS, the least-squares plane through the 5-bromoisatin fragment forms a dihedral angle of 13.63 (14) with the phenyl ring. The molecular conformation features intramolecular N-HÁ Á ÁN and N-HÁ Á ÁO hydrogen bonds. In the crystal, molecules are connected via pairs of N-HÁ Á ÁO interactions into centrosymmetric dimers. Additionally, stacking interactions link molecules into chains parallel to the a axis with short CÁ Á ÁC distances being observed between the phenyl and thiocarbonyl [3.236 (8) Å ] groups and between the thiocarbonyl and carbonyl [3.351 (4) Å ] groups of stacked molecules.

Experimental
The starting materials were commercially available and were used without further purification. The 5-bromoisatine-3-(4phenyl)thiosemicarbazone synthesis was adapted from a procedure reported previously (Campaigne & Archer, 1952). The hydrochloric acid catalyzed reaction of 5-bromoisatin (8.83 mmol) and (4-phenyl)thiosemicarbazide (8.83 mmol) in a 1:1 mixture of ethanol and water (50 ml) was refluxed for 6 h. After cooling and filtering, the title compound was obtained.
Crystals suitable for X-ray diffraction of the title compound were obtained by the slow evaporation of the solvents.

Refinement
All C-H and N-H H atoms were located in difference map, but were positioned with idealized geometry and were refined isotropically with U iso (H) = 1.2 U eq (C, N) using a riding model with C-H = 0.93 Å for aromatic and N-H = 0.88 Å for N-bound H atoms.

Computing details
Data collection: X-AREA (Stoe & Cie, 2008); cell refinement: X-AREA (Stoe & Cie, 2008); data reduction: X-RED32 (Stoe & Cie, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).  The molecular structure of the title compound with labeling and displacement ellipsoids drawn at the 40% probability level.   Crystal structure of the title compound in a view along the crystallographic c-axis. The π-π-interactions are drawn as dashed lines, highlighting C···C distances ranging from 3.236 (8) to 3.471 (7) Å. The molecular arrangment in layers, stacked into the direction of the crystallographic a-axis, is simplified for clarity. where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.67 e Å −3 Δρ min = −1.11 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 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.