(N,N-Di-allyl-dithio-carbamato-κ2 S,S')tri-phenyltin(IV) and bis-(N,N-di-allyl-dithio-carbamato-κ2 S,S')di-phenyl-tin(IV): crystal structure, Hirshfeld surface analysis and computational study

The crystal and mol-ecular structures of the title organotin di-thio-carbamate compounds, [Sn(C6H5)3(C7H10NS2)] (I) and [Sn(C6H5)2(C7H10NS2)2] (II), present very distinct tin atom coordination geometries. In (I), the di-thio-carbamate ligand is asymmetrically coordinating with the resulting C3S2 donor set defining a coordination geometry inter-mediate between square-pyramidal and trigonal-bipyramidal. In (II), two independent mol-ecules comprise the asymmetric unit, which differ in the conformations of the allyl substituents and in the relative orientations of the tin-bound phenyl rings. The di-thio-carbamate ligands in (II) coordinate in an asymmetric mode but the Sn-S bonds are more symmetric than observed in (I). The resulting C2S4 donor set approximates an octa-hedral coordination geometry with a cis-disposition of the ipso-carbon atoms and with the more tightly bound sulfur atoms approximately trans. The only directional inter-molecular contacts in the crystals of (I) and (II) are of the type phenyl-C-H⋯π(phen-yl) and vinyl-idene-C-H⋯π(phen-yl), respectively, with each leading to a supra-molecular chain propagating along the a-axis direction. The calculated Hirshfeld surfaces emphasize the importance of H⋯H contacts in the crystal of (I), i.e. contributing 62.2% to the overall surface. The only other two significant contacts also involve hydrogen, i.e. C⋯H/H⋯C (28.4%) and S⋯H/H⋯S (8.6%). Similar observations pertain to the individual mol-ecules of (II), which are clearly distinguishable in their surface contacts, with H⋯H being clearly dominant (59.9 and 64.9%, respectively) along with C⋯H/H⋯C (24.3 and 20.1%) and S⋯H/H⋯S (14.4 and 13.6%) contacts. The calculations of energies of inter-action suggest dispersive forces make a significant contribution to the stabilization of the crystals. The exception is for the C-H⋯π contacts in (II) where, in addition to the dispersive contribution, significant contributions are made by the electrostatic forces.