(Pyridin-4-yl)methyl N′-(3-phenylallylidene)hydrazinecarbodithioate

In the title compound, C16H15N3S2, the central C2N2S2 residue is planar (r.m.s. deviation = 0.045 Å) and the pyridyl and benzene rings are inclined and approximately coplanar to this plane, respectively [dihedral angles = 72.85 (9) and 10.73 (9)°], so that, overall, the molecule adopts an L-shape. The conformation about each of the N=C [1.290 (3) Å] and C=C [1.340 (3) Å] bonds is E. Supramolecular chains along [1-10] are stabilized by N—H⋯N(pyridine) hydrogen bonding and these are connected into a double layer that stacks along the c-axis direction by C—H⋯π(pyridine) interactions.

In the title compound, C 16 H 15 N 3 S 2 , the central C 2 N 2 S 2 residue is planar (r.m.s. deviation = 0.045 Å ) and the pyridyl and benzene rings are inclined and approximately coplanar to this plane, respectively [dihedral angles = 72.85 (9) and 10.73 (9) ], so that, overall, the molecule adopts an L-shape. The conformation about each of the N C [1.290 (3) Å ] and C C [1.340 (3) Å ] bonds is E. Supramolecular chains along [110] are stabilized by N-HÁ Á ÁN(pyridine) hydrogen bonding and these are connected into a double layer that stacks along the c-axis direction by C-HÁ Á Á(pyridine) interactions.
In (I), Fig. 1, the central C 2 N 2 S 2 residue is planar (r.m.s. deviation = 0.045 Å) with maximum deviations of 0.040 (2) Å for each of N1 and C11, and -0.048 (1) Å for the S1 atom. The pyridyl ring is inclined to this plane, forming a dihedral angle of 72.85 (9) °, whereas the benzene ring is almost co-planar [dihedral angle = 10.73 (9) bonds is E. Globally, the molecule adopts an L-shape as the pyridyl residue is anti to the thione-S2 atom. A very similar conformation was found in the benzyl ester (Tarafder et al., 2008).
The pyridyl ring proves pivotal in the crystal packing by forming a hydrogen bond with the amine-N1-H atom and acting as an acceptor in a C-H···π(pyridyl) contact, Table 1. The hydrogen bonding leads to the formation of supramolecular chains along [1 1 0] and these are connected into a double layer in the ab plane via the C-H···π(pyridyl) contacts, Fig. 2.
Potassium hydroxide (11.4 g, 0.2 mol) was dissolved completely in 90% ethanol (70 ml) and the mixture was cooled in ice. To the cold solution, hydrazine hydrate (9.7 ml, 0.2 mol) was added slowly with stirring. Carbon disulfide (12.0 ml, 0.2 mol) was then added drop-wise with vigorous stirring for about 1 h. The temperature of the reaction mixture was kept below 268 K during addition. During this time two layers formed. The resulting yellow oil (lower layer) was separated and dissolved in 40% ethanol (60 ml). 4-Picolylchloride hydrochloride (32.8 g, 0.2 mol) was completely dissolved in 100 ml of 80% ethanol and added slowly to the above solution with vigorous mechanical stirring. The resulting white product (S4PDTC) was separated by filtration, washed with water and dried. The crude product was recrystallized from absolute ethanol.

Refinement
Carbon-bound H-atoms were placed in calculated positions (C-H 0.95 to 0.99 Å) and were included in the refinement in the riding model approximation, with U iso (H) = 1.2U equiv (C). The nitrogen-bound H-atom was refined with N-H = 0.88±0.01 Å. The (0 3 14) reflection was omitted from the final refinement owing to poor agreement.

Figure 1
The molecular structure of (I) showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level.   Special details Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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.