(E)-2-Hydroxy-3-methoxybenzaldehyde thiosemicarbazone

In the title compound, C9H11N3O2S, intramolecular O—H⋯O and N—H⋯N hydrogen bonds contribute to the planarity of the molecular skeleton. Intermolecular N—H⋯O hydrogen bonds link the molecules into zigzag chains along the b axis; these molecules are futher paired by π–π interactions [centroid–centroid distance 4.495 (5) Å]. The crystal structure also exhibits weak intermolecular N—H⋯S and O—H⋯S hydrogen bonds.

In the title compound, C 9 H 11 N 3 O 2 S, intramolecular O-HÁ Á ÁO and N-HÁ Á ÁN hydrogen bonds contribute to the planarity of the molecular skeleton. Intermolecular N-HÁ Á ÁO hydrogen bonds link the molecules into zigzag chains along the b axis; these molecules are futher paired byinteractions [centroid-centroid distance 4.495 (5) Å ]. The crystal structure also exhibits weak intermolecular N-HÁ Á ÁS and O-HÁ Á ÁS hydrogen bonds.

Comment
Thiosemicarbazone Schiff-bases have been investigated in terms of their chemistry and potentially beneficial biological activities, such as antitumor, antibacterial, antiviral and antimalarial activities (Kasuga et al., 2001;Fonari et al., 2003).
In continuation of our studies on thiosemicarbazone Schiff-bases, we report the synthesis and crystal structure of the title compound, (I).
In (I) (Fig. 1), all bond lengths and angles are normal and in a good agreement with those found in the literature (Joseph et al., 2006). The intramolecular O-H···O and N-H···N hydrogen bonds (Table 2) contribute to the planarity of molecular skeleton. The intermolecular N-H···O hydrogen bonds (Table 2) link the molecules into zigzag chains along b axis, which are futher paired by π···π interactions proved by short intermolecular C···C distances ( Table 1). The crystal packing exhibits also weak intermolecular N-H···S and O-H···S hydrogen bonds (Table 2).

Experimental
The title compound was synthesized by the reaction of 2-hydroxy-3-methoxybenzaldehyde (0.152 g, 1 mmol) and hydrazinecarbothioamide (0.091 g, 1 mmol) in ethanol solution and stirred under reflux conditions (353 K) for 6 h. When cooled to the room temperature, the solution was filtered off and after a week orange crystals suitable for X-ray diffraction study were obtained. Yield, 0.199 g, 82%. m.p. 358-360 K.

Refinement
The H-atoms were geometrically positioned (C-H 0.93-0.96 Å, N-H 0.86 Å, O-H 0.82 Å), and refined as riding on their parent atoms, with U iso (H) = 1.2U eq (C-aromatic and N) and U iso (H) = 1.5U eq (C-methyl and O). Fig. 1. The molecular structure of (I) showing the atomic numbering and 30% probability displacement ellipsoids.

Figures
(E)-2-Hydroxy-3-methoxybenzaldehyde thiosemicarbazone as those based on F, and R-factors based on ALL data will be even larger.