3-Methoxybenzaldehyde thiosemicarbazone

The title compound, C9H11N3OS, was prepared by the reaction of 3-methoxybenzaldehyde and thiosemicarbazide. The benzylidene ring and the thiosemicarbazone fragment are slightly twisted, making a dihedral angle of 14.1 (1)°. A weak intramolecular N—H⋯N hydrogen bond may influence the conformation of the molecule. Intermolecular N—H⋯S hydrogen bonds build up a three-dimensional network.

The title compound, C 9 H 11 N 3 OS, was prepared by the reaction of 3-methoxybenzaldehyde and thiosemicarbazide. The benzylidene ring and the thiosemicarbazone fragment are slightly twisted, making a dihedral angle of 14.1 (1) . A weak intramolecular N-HÁ Á ÁN hydrogen bond may influence the conformation of the molecule. Intermolecular N-HÁ Á ÁS hydrogen bonds build up a three-dimensional network.
Experimental Crystal data

Comment
Thiosemicarbazones constitute an important class of N,S donor ligands due to their propensity to react with a wide range of metals (Casas et al., 2000). Thiosemicarbazones exhibit various biological activities and have therefore attracted considerable pharmaceutical interest (Maccioni et al., 2003;Ferrari et al., 2000). They have been evaluated as antiviral, antibacterial and anticancer therapeutics. Thiosemicarbazones belong to a large group of thiourea derivatives, whose biological activities are a function of parent aldehyde or ketone moiety (Chimenti et al., 2007). Schiff bases show potential as antimicrobial and anticancer agents (Tarafder et al., 2000;Deschamps et al., 2003) and so have biochemical and pharmacological applications.
We here report the crystal structure of the title compound (I).
The sulfur atom and the hydrazine nitrogen N1 are in trans position with respect to the C9-N2 bond. This conformation may be induced by the weak intramolecular N-H···N hydrogen bond ( Fig. 1, Table 1). All bond lengths are within normal ranges (Allen et al., 1987).
At first glance the molecule is roughly planar with the largest deviation from the mean plane being -0.272 (3) Fig. 1. A view of the molecular structure of (I) showing the atom-numbering scheme and 30% displacement ellipsoids. H atoms are represented as smal sphere of arbitrary radii. Intramolecular hydrogen bond is shown as dashed line.

Special details
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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq S1 0.51511 (