Cis/trans isomers of PtX 2 L 2 (X = halogen, L = neutral ligand); the crystal structures of two polymorphs of cis-dichlorobis(dibenzyl sulfido-κS)platinum(II) in the temperature range 100–295 K

Abstract

The structures of two polymorphs, one triclinic and one monoclinic, of cis-dichlorobis(dibenzyl sulfido-κS)platinum(II), cis-PtCl2(Bz2S)2, have been determined at 295, 250, 200, 150 and 100 K. In both polymorphs the complex has a structure where platinum(II) coordinates two dibenzyl sulfide molecules and two chloro ligands, forming a complex with pseudo-square-planar coordination geometry. The triclinic polymorph shows disorder at all temperatures. Both polymorphs have a packing arrangement involving centrosymmetric structural dimers. cis-PtCl2(Bz2S)2 belongs to a group of complexes with the general formula PtX 2 L 2, where X is a halogen and L is a ligand with a donor atom from groups 14, 15 or 16. The distribution of structural classes among 173 cis-PtX 2 L 2 compounds found in the Cambridge Structural Database (CSD, Version 5.28, November 2006) has been investigated. The predominant structural class [notation according to Belsky & Zorkii (1977). Acta Cryst. A33, 1004–1006] among the cis compounds is P21/c, Z = 4 (1) (73 structures, 42%), followed by P\bar 1, Z = 2 (1) (33 structures, 19%). Inversion centres combined with the screw-axis/glide plane are the dominating packing operators (56%) followed by the inversion centre (21%). The cis and trans influence in cis/trans-PtCl2 L 2 compounds has been investigated using data from the CSD. The cis influence is small for donor atoms in groups 15 and 16. The trans influence is small for group 16 donor atoms and for nitrogen, but for phosphorus it is significantly greater than the other donor atoms studied.