1-(Biphenyl-4-ylmethylidene)thiosemicarbazide monohydrate

In the title compound, C14H13N3S·H2O, the thiosemicarbazide group is nearly planar, with a maximum deviation of 0.072 (2) Å from the ideal least-squares plane, and shows an E conformation. In the crystal packing, the water molecules are involved in an extensive intermolecular N—H⋯O hydrogen-bond network, assisted by O—H⋯S interactions, which link the independent molecules into chains extended along b axis. An intramolecular hydrogen N—H⋯N bond helps to stabilize the molecular conformation.

In the title compound, C 14 H 13 N 3 SÁH 2 O, the thiosemicarbazide group is nearly planar, with a maximum deviation of 0.072 (2) Å from the ideal least-squares plane, and shows an E conformation. In the crystal packing, the water molecules are involved in an extensive intermolecular N-HÁ Á ÁO hydrogen-bond network, assisted by O-HÁ Á ÁS interactions, which link the independent molecules into chains extended along b axis. An intramolecular hydrogen N-HÁ Á ÁN bond helps to stabilize the molecular conformation.

Experimental
Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell refinement: CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED; program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2009 Thiosemicarbazides, a class of compounds possessing a wide spectrum of potential medicinal applications, have been studied for their antitumoral, antiviral, antibacterial, antimalarial, antifungal, anti-inflammatory and anti-HIV activities (West et al., 1991). These properties are thought to arise from the metal-chelating ability of these ligands. In almost all cases, the ligands are bidentate and bind to the metal through the S and hydrazinic N atoms, although there are examples of them acting as monodentate ligands binding only through sulfur (Kowol et al., 2007).
The title compound C 14 H 13 N 3 S.H 2 O was synthesized and its crystal structure is reported here. This compound is likely to have biomedical properties similar to other nitrogen-sulfur donor ligands. The asymmetric unit consists of a single molecule (I), shown in Figure 1. The thiosemicarbazide adopts an E conformation with a trans configuration observed about the C=N bond. The thiosemicarbazide moiety is planar, the C(14)-N(2) (1.341 (3) Å) and N(1)-N(2) (1.371 (3) Å) bond lengths imply significant electron delocalization and the C13/N1/N2/C14/S1 fragment is close to planar (max. deviation = 0.072 (2) Å). The dihedral angle between benzene ring C7/C8/C9/C10/C11/C12 and the moiety C13/N1/N2/C14/S1 is 4.67 (1)°. This value suggests that they are nearly coplanar, and π-electrons are delocalized in the benzaldehyde thiosemicarbazide fragment.  (Table 1) contributes to stabilize the molecular conformation. The intermolecular distance value between ring centroids in the b axis direction (6.350 Å), suggests that there is no π-stacking interaction between parallel molecules ( Figure 2).
Completeness of the reaction was TLC controlled indicating the disappearance of the aldehyde spot. On cooling to room temperature the precipitate was filtered off, washed with copious cold methanol and dried in air (yield: 1.581 g, 61%; m.p. 475 K). Yellow single crystals compound were obtained after recrystallization from a solution of chloroform/methanol (3:7 v/v) after 10 days at room temperature.

Refinement
At the end of the refinement the highest peak in the electron density was 0.3350 e Å -3 , while the deepest hole was -0.3210 e Å -3 .
supplementary materials sup-2 Figures   Fig. 1. A view of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.  Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 Rfactors(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.