2-(1,2,3,4-Tetrahydronaphthalen-1-ylidene)hydrazinecarbothioamide

The molecular structure of the title compound, C11H13N3S, is not planar: the maximum deviation from the mean plane of the non-H atoms is 0.521 (2) Å for an aliphatic C atom, which corresponds to an envelope conformation for the non-aromatic ring. The hydrazinecarbothioamide substituent and the benzene ring have maximum deviations from the mean planes through the non-H atoms of 0.0288 (16) and 0.0124 (27) Å, respectively, and the dihedral angle between the two planes is 8.84 (13)°. In the crystal, molecules are linked into chains along [10] by pairs of N—H⋯S hydrogen bonds between molecules related by centres of symmetry.

In the crystal structure of the title compound the maximum deviation from the least squares plane through all nonhydrogen atoms is 0.5205 (23) Å for C3, which is in agreement with the envelope conformation observed for the nonaromatic ring (Fig. 1).
The trans conformation for the thiosemicarbazone fragment is also observed in other structures (Pederzolli et al., 2011 andBittencourt et al., 2012).  Table 1).

Experimental
All starting materials were commercially available and were used without further purification. The synthesis was adapted from a procedure reported previously (Thanigaimalai et al., 2011). The hydrochloric acid catalyzed reaction of 1tetralone (10 mmol) and thiosemicarbazide (10 mmol) in a 3:1 mixture of ethanol and water (100 ml) was refluxed for 7 h. After cooling and filtering, crystals suitable for X-ray diffraction were obtained by recrystallization from tetrahydrofurane.

Refinement
All non-hydrogen atoms were refined anisotropically. C-H H atoms were positioned with idealized geometry and were refined isotropically, with U iso (H) = 1.2 U eq (C) using a riding model with C-H = 0.97 Å for aromatic and 0.93 Å for methylene H atoms. N-H H atoms were located in difference map, their bond lengths set to 0.89 Å and finally they were refined isotropically with U iso (H) = 1.2 U eq (N) using a riding model.

Figure 1
Molecular structure of the title compound with labeling and displacement ellipsoids drawn at the 40% probability level. 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.