Christian Hansson

Cis/trans isomers of PtX2L2 (X = halogen, L = neutral ligand); the crystal structure of trans-dichlorobis(dimethyl sulfide)platinum(II) and the pressure dependence of its unit-cell dimensions

trans-PtCl(2)(dms)(2) (dms is dimethyl sulfide) crystallizes in the space group P2(1)/n and adopts the molecular point group C(i), which is the most frequently occurring point group for trans-PtX(2)L(2) complexes (78%), as observed in the Cambridge Structural Database (CSD; 2005 release), followed by C(1) (16%). Density functional theory calculations show that the observed geometry for trans-PtCl(2)(dms)(2) has slightly higher energy than the most favorable geometry in the point group C(2h), but this geometry would require a space group that hampers close packing, thus showing that intermolecular forces determine the point group for the title compound. High-pressure powder diffraction studies of trans-PtCl(2)(dms)(2) show no phase transformation up to 8.0 GPa. The bulk modulus is 8.1 (6) GPa and the pressure derivative 8.1 (4). In the CSD, the number of cis- and trans-PtX(2)L(2) compounds are almost equal, viz. 156 cis and 160 trans compounds, showing no preference for either isomer in the solid state.

cis/trans isomers of PtX2L2(X=halogen, L=neutral ligand); the crystal structures of two polymorphs of cis-dichlorobis(dibenzyl sulphidokS)platinum(II) in the temperature range 100-295 K.

The structures of two polymorphs, one triclinic and one monoclinic, of cis-dichlorobis(dibenzyl sulfido-kappaS)platinum(II), cis-PtCl(2)(Bz(2)S)(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-PtCl(2)(Bz(2)S)(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 P2(1)/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-PtCl(2)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.

cis‐Bis(acetato‐κO)bis(dimethyl sulfide‐κS)platinum(II)

The title compound, cis-[Pt(CH3COO)2(C2H6S)2], crystallizes in the P2(1)/c space group with a pseudo-square-planar coordination geometry. The complex forms centrosymmetric dimeric packing units, with C-H...O-Pt interactions and a short Pt...Pt distance [3.5868 (2) A]. The coordination mode of the acetate ligands is monodentate and they are oriented almost perpendicular to the coordination plane. Cambridge Structural Database [Allen (2002). Acta Cryst. B58, 380-388] data show a preferred staggered conformation with respect to the coordination plane for Me2S in complexes with Pt(II).

cis-Bis(acetato-kO)bis(dimethyl sulfide-kS)platinum(II)

The title compound, cis-[Pt(CH3COO)2(C2H6S)2], crystallizes in the P2(1)/c space group with a pseudo-square-planar coordination geometry. The complex forms centrosymmetric dimeric packing units, with C-H...O-Pt interactions and a short Pt...Pt distance [3.5868 (2) A]. The coordination mode of the acetate ligands is monodentate and they are oriented almost perpendicular to the coordination plane. Cambridge Structural Database [Allen (2002). Acta Cryst. B58, 380-388] data show a preferred staggered conformation with respect to the coordination plane for Me2S in complexes with Pt(II).

cis-Dichloridobis(diethyl sulfide-kappa S) platinum(II) at 295 and 150 K

The title compound, cis-[PtCl(2)(C(4)H(10)S)(2)], crystallizes in the space group P2(1)/n with pseudo-square-planar coordination geometry. The orientation of the ethyl groups on the S atoms is staggered with respect to the coordination plane, giving the complex approximate C(2v) symmetry. The complex does not form dimeric packing units with short Pt...S intradimeric distances as seen in some related complexes, but instead displays C-H...Cl interactions in three dimensions. These C-H...Cl-Pt contacts are compared with those of related compounds reported in the Cambridge Structural Database, which show a frequency maximum in the range 120-170 degrees for the C-H...Cl angle.

Dibenzyl sulfide at 150 K

The mol-ecule of the title compound, C14H14S, lies on a crystallographic twofold axis running through the central S atom, and hence mol-ecules have exact C-2 mol-ecular symmetry. Density-functional theory calculations reveal that the energy-optimized mol-ecular structure in the gas phase is close to that observed in the crystal structure. The crystal packing is dominated by double chains running along the c axis formed by C-(HS)-S-... inter-actions.

Hexafluorophosphates of chlorotris(dimethyl sulfide)platinum(II) and bromotris (dimethyl sulfide)platinum(II)

The title compounds, chlorotris(dimethyl sulfide-kappaS)platinum(II) hexafluorophosphate, [PtCl(C(2)H(6)S)(3)]PF(6), and bromotris(dimethyl sulfide-kappaS)platinum(II) hexafluorophosphate, [PtBr(C(2)H(6)S)(3)]PF(6), are isomorphous and are composed of [PtX(dms)(3)](+) complex cations (X = Cl and Br, and dms is dimethyl sulfide) and PF(6)(-) anions. The Pt atom is coordinated by three S atoms and one X atom in a pseudo-square-planar coordination, with Pt-S distances in the range 2.293 (1)-2.319 (2) A. Two dms ligands have a staggered conformation with respect to the coordination plane, while the third is rotated by approximately 90 degrees compared with the orientation of the other two. The packing can be described as consisting of [PtX(dms)(3)](2)(PF(6))(2) units with a centre of symmetry. In this description, the Pt(II) atom has a pseudo-octahedral coordination, with four normal bonds and two long weak interactions. Density-functional theory calculations show that a conformation in which one dms ligand is not staggered is less favourable than having all three dms ligands staggered.