Dichlorido{4-cyclohexyl-1-[1-(2-pyridyl-κN)ethylidene]thiosemicarbazidato-κ2 N 1,S}phenyltin(IV)

The SnIV atom in the title compound, [Sn(C6H5)(C14H19N4S)Cl2], exists within a distorted octahedral geometry defined by the N,N′,S-tridentate monodeprotonated Schiff base ligand, two mutually trans Cl atoms, and the ipso-C atom of the Sn-bound phenyl group; the latter is trans to the azo-N atom. The greatest distortion from the ideal geometry is found in the nominally trans angle formed by the S and pyridyl-N atoms at Sn [151.03 (4)°]. With the exception of the cyclohexyl group (chair form), the Schiff base ligand is almost planar (r.m.s. deviation of non-H and Sn atoms = 0.053 Å). The nearly orthogonal orientation of the Sn-bound phenyl group [N—Sn—C—C torsion angle = 70.8 (5)°] to the planar portion of the Schiff base allows for the formation of significant intramolecular C—H⋯Cl interactions which preclude the Cl atoms from participating in N—H⋯Cl hydrogen bonds. Instead, C—H⋯π contacts, involving methylene H and the Sn-bound phenyl group, lead to the formation of supramolecular chains that pack in the bc plane. Connections between these layers are of the type C—H⋯Cl.

The Sn IV atom in the title compound, [Sn(C 6 H 5 )(C 14 H 19 -N 4 S)Cl 2 ], exists within a distorted octahedral geometry defined by the N,N 0 ,S-tridentate monodeprotonated Schiff base ligand, two mutually trans Cl atoms, and the ipso-C atom of the Sn-bound phenyl group; the latter is trans to the azo-N atom. The greatest distortion from the ideal geometry is found in the nominally trans angle formed by the S and pyridyl-N atoms at Sn [151.03 (4) ]. With the exception of the cyclohexyl group (chair form), the Schiff base ligand is almost planar (r.m.s. deviation of non-H and Sn atoms = 0.053 Å ). The nearly orthogonal orientation of the  ] to the planar portion of the Schiff base allows for the formation of significant intramolecular C-HÁ Á ÁCl interactions which preclude the Cl atoms from participating in N-HÁ Á ÁCl hydrogen bonds. Instead, C-HÁ Á Á contacts, involving methylene H and the Sn-bound phenyl group, lead to the formation of supramolecular chains that pack in the bc plane. Connections between these layers are of the type C-HÁ Á ÁCl.

Related literature
For the structure of the methyltin derivative, see: Salam et al. (2010).
Cg1 is the centroid of the C15-C20 benzene ring.  The Sn atom in (I), Fig. 1, exists within a six atom CCl 2 N 2 S donor set defined by the tridentate monodeprotonated Schiff base ligand, two mutually trans chlorido atoms, and the ispo-C atom of the Sn-bound phenyl group which is trans to the azo-N atom, Table 1. Distortions from the ideal octahedral geometry are ascribed primarily to the restricted bite distances formed by the Schiff base which results in an angle of 151.03 (4) ° for the nominally trans S1-Sn-N1 angle.
The disposition of donor atoms resembles that found in the structure of the methyltin derivative (Salam et al., 2010). With the exception of the cyclohexyl group, which adopts a chair conformation, the Schiff base ligand is planar. Thus, the r.m.s. deviation from the least-squares plane through the 15 non-H atoms in the conjugated part of the ligand including the Sn and methine-C15 atoms, i.e. Sn,S1,N1-N4,C1-C9, is 0.053 Å. The Sn-bound phenyl group occupies a position almost orthogonal to the chelate rings as seen in the N2-Sn-C15-C16 torsion angle of 70.8 (5) Å.
In the crystal, supramolecular chains along the b axis are mediated by C-H···π interactions involving a methylene-H interacting with the Sn-bound phenyl group, Table 1. The chains pack in the bc plane and connections between the layers stacked along the a axis are of the type C-H···Cl, Fig. 2 and Table 1. The non-participation of the N-H atom in forming a significant intermolecular interaction contrasts the formation of N-H···Cl interactions in the methyltin derivative (Salam et al., 2010). It is noted that the orthogonal orientation of the Sn-bound phenyl group allows for the formation of close intramolecular C-H···Cl contacts, Table 1, which probably deactivate the chlorido atoms from forming significant hydrogen bonds. Further, it is noted that the C-H···π interactions present in (I) involves the Sn-bound phenyl group as as the acceptor, and that these are not possible in the methyltin derivative. Together, these factors explain the absence of significant hydrogen bonding interactions involving the N-H atom.
Experimental 2-Acetylpyridine-N-cyclohexyl thiosemicarbazone (0.28 g, 1.0 mmol) was dissolved in absolute methanol (10 ml) in a Schlenk round bottom flask under a nitrogen atmosphere and stirred for 30 min. Then, a 10 ml me thanolic solution of phenyltin(IV) trichloride (0.302 g, 1.0 mmol) was added drop wise while stirring which resulted in the formation of a yellow solution. The reaction mixture was refluxed for 4 h. and then cooled to room temperature. Yellow micro crystals of (I) were obtained from the slow evaporation of the solution at room temperature. The micro crystals were filtered off, washed with a small amount of cool methanol and dried in vacuo over silica gel. Light-yellow crystals were obtained from the slow evaporation of a chloroform/methanol (1/1) solution of (I) held at room temperature. Carbon-bound H-atoms were placed in calculated positions (C-H = 0.95 to 1.00 Å) and were included in the refinement in the riding model approximation, with U iso (H) set to 1.2-1.5U equiv (C). The N-bound H atom was located from a difference map and refined with the distance restraint N-H = 0.88±0.01 Å, and with U iso (H) = 1.2U eq (N). Fig. 1. The molecular structure of (I) showing displacement ellipsoids at the 50% probability level. Crystal data [Sn(C 6