Crystal structure and mass spectrometry of dichlorodimethylbis[2(1H)-pyridinethione-S]tin(IV)

Abstract

The structure of the complex Sn(CH₃)₂Cl₂·2C₅H₅NS has been determined by single-crystal X-ray diffraction methods. The compound crystallizes in the monoclinic system, space group P2₁/n, with unit-cell dimensions a= 16.793(5), b= 6.201(3), c= 7.882(3)Å, β= 90.4(3)°, and Z= 2. The configuration about the tin atom is all-trans octahedral. The C₅H₅NS ligands are bonded to the metal through the S atom. The observed C(2)–S bond length [1.730(g)Å] is consistent with ca. 35% double-bond character, compared to ca. 55% for the uncomplexed ligand. The H atoms on the N atoms are involved in intramolecular hydrogen bonding with the chloride ligands, N–H ⋯ Cl 3.199(9)Å. Mass spectra of Sn(CH₃)₂Cl₂·2C₅H₅NS show that facile elimination of HCl from the complex occurs to give a series of ions containing the ligand C₅H₄NS; these can be formulated as complexes of the 2-pyridinethiolate anion, probably bonded through the S atom. Mass spectra of the metastable ion [Sn(CH₃)Cl(C₅H₄NS)]⁺ show that the Sn–L bond strengths are in the order L = methyl < chlorine < 2-pyridinethiolate.