cis-Bis(acetato-kappaO)bis(dimethyl sulfide-kappaS)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-trans isomers of PtX4L2 (X = halogen and L = neutral ligand): trans-bis(dimethyl sulfide)tetraiodidoplatinum(IV).

The octahedral title complex, [PtI4(C2H6S)2] or trans-PtI4(dms)2 (dms is dimethyl sulfide), crystallizes in the monoclinic space group P2(1)/n (Z = 2), with molecular symmetry C(i), which is the most frequently occurring point group for trans-PtX4L2 {56%, 28 structures in the Cambridge Structural Database (CSD) [Allen (2002). Acta Cryst. B58, 380-388]}, followed by C(1) (22%, 11 structures). The complexes form a puckered pseudo-hexagonal layer in the (10(1)) plane, and the layers are stacked with an interplanar distance of 7.10 A. Density functional theory (DFT) calculations on an isolated complex with the observed parameters as a starting structure converged to C(2h). Constraints to C(i) on the observed geometry give 3-4 kJ mol(-1) higher energy compared with C(2h). DFT calculations on [PtCl4(PzH)2] (PzH is pyrazole), reported in the CSD in both the cis and trans forms, show an energy difference of 21 kJ mol(-1) in favour of the trans complex. A CSD search for PtX4L2-type complexes, where X is a halogen and L is a ligand with a donor atom from group 14, 15 or 16, indicated a preferred trans geometrical arrangement, with a total fraction of 68%. The dominating crystal packing operators for the trans complexes are an inversion centre combined with a screw axis/glide plane (48%), followed by an inversion centre alone (28%).

Cis/trans isomers of PtX(2)L(2) (X = halogen, L = neutral ligand); the crystal structures of two polymorphs of cis-dichlorobis(dibenzyl sulfido-kappaS)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(dimethyl sulfide)dinitratoplatinum(II) at 295 and 150 K.

The title compound, [Pt(NO(3))(2)(C(2)H(6)S)(2)], crystallizes in the P2(1)/n space group (Z' = 2), with pseudo-square-planar coordination geometry. The complex forms dimers with pseudosymmetry C(i) arranged in columns along the b-axis direction, with Pt...Pt distances of 6.3056 (3) and 4.2382 (2) A (at 150 K). Each column is surrounded by six other columns in a honeycomb rod-like packing. The coordination mode of the nitrate ligands is monodentate, with Pt-O-N angles ranging from approximately 117 to approximately 118 degrees and a tilt between the nitrate ligands and the coordination planes in the range approximately 63-70 degrees (at 150 K). The coordination mode of the nitrate ligands is compared with that observed in reported Pt(NO(3))(2)L(2) complexes (where L is a ligand with a donor atom from group 15 or 16), all of which are monodentate, with an average Pt-O-N angle of 118 (2) degrees and a tilt in the range 90 +/- 30 degrees (with two exceptions, in which the nitrates are approximately in the coordination plane).

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.

Tetrakis(dimethyl sulfide)palladium(II) bis(tetrafluoroborate) and tetrakis(1,4-oxathiane-kappaS)palladium(II) bis(tetrafluoroborate).

Tetrakis(dimethyl sulfide)palladium(II) bis(tetrafluoroborate), [Pd(C(2)H(6)S)(4)](BF(4))(2), (I), and tetrakis(1,4-oxathiane-kappaS)palladium(II) bis(tetrafluoroborate), [Pd(C(4)H(8)OS)(4)](BF(4))(2), (II), both crystallize as mononuclear square-planar complexes with tetrafluoroborate as the counter-ions. The Pd atom accepts four S-donor atoms and is positioned at an inversion centre in both compounds. The two unique S atoms in the dimethyl sulfide complex, (I), are disordered. The Pd-S distances are in the range 2.3338(12)-2.3375(12)A in (I), and the corresponding distances in the thioxane complex, (II), are 2.3293(17) and 2.3406(17)A. The anions in both compounds interact weakly with the Pd atom.

Structures of trans-[PtCl(2)(PBz(3))(2)], trans-[PtI(2)(PBz(3))(2)], trans-[Pt(NCS)(2)(PBz(3))(2)].0.5C(6)H(6) and trans-[PdI(2)(PBz(3))(2)].

A series of structures of trans-[MX(2)(PBz(3))(2)] [M = Pt, X = Cl(-); PBz(3) = tribenzylphosphine (1), I(-), trans-diiodobis(tribenzylphosphine)platinum(II) (2), and NCS(-), trans-di(thiocyanate)bis(tribenzylphosphine)platinum(II) (3); M = Pd, X = I(-), trans-diiodobis(tribenzylphosphine)palladium(II) (4)] have been characterized by X-ray crystallography. In all compounds each tribenzylphosphine has one benzylcarbon close to the coordination plane. In (1), (2) and (4) those (in-plane) C atoms, from the two different PBz(3), exhibit an anti conformation along the P-P axis, while (3) has the gauche conformation. Root mean square (RMS) calculations and half-normal probability plots show that the complexes in (2) and (4) are very similar and the only significant differences between them are the M-P bonds, 2.354 (4) and 2.330 (5) A, and the M-I bond distances, 2.604 (1) and 2.611 (2) A, for Pd and Pt, respectively. Calculations of the steric demand of the PBz(3) ligands based on the Tolman model gave values ranging from 155 to 178 degrees for the effective and 156 to 179 degrees for the Tolman angles, respectively.

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.