Karin Lövqvist

Trans influence in platinum(II) complexes. Phenylation of Pt(II) dialkylsulfide complexes by BPh4− and SnPh3H. Crystal structures of two polymorphs of trans-chlorobis(dimethylsulfide)(phenyl)platinum(II)

Two methods of phenylation of platinum(II) complexes are described, one by heating [PtCl(dms)3](BPh4) and another starting from triphenyltin hydride and [PtCl2(dms)2], dms = dimethylsulfide. Two different polymorphs of trans-[PtPhCl(dms)2] are obtained, one monoclinic and one triclinic. The monoclinic form contains two crystallographically different complexes. The main difference between the molecular geometries in the polymorphs is the orientation of the dms ligands. Distances found are PtCl, 2.403–2.420; PtS, 2.279–2.298 and PtC, 1.99–2.00 A. A comparison of some PtCl bond distances obtained from the literature reveals that the trans influence increases in the following order: Cl < S ⪕ Sn, P < C, H < Si.

PHENYLATION OF PLATINUM(II) THIOETHER COMPLEXES BY TETRAPHENYLBORATE(III) IN SOLID STATE AND NITROMETHANE SOLUTION

Abstract Platinum(II) complexes of the type [Pt(thioether)3Cl]+ (thioether = dimethyl sulfide, thioxane) are capable of abstracting a phenyl group from the BPh− 4 counterion with formation of trans-[Pt(thioether)2ClPh] compounds. Thermal reactions proceed both in the solid phase and in nitromethane solution at elevated temperature and have preparative importance. Phenylation of the Pt(II) centre also occurs in reaction between [Pt(Me2S)2Cl2] and AgBPh4 in CH2Cl2 suspension. Brief X-ray crystallographic structural data for trans-[Pt(Me2S)2ClPh] and [Pt(thioether)3Cl]X (thioether = Me2S, tx, X = SO3CF3; thioether = Me2S, X = PF6) are reported.

New methods for synthesis of platinum(II) dimethyl sulfide complexes

Abstract Different methods for the synthesis of anionic dimethyl sulfide platinum complexes of the type Q[PtCl 3 (Me 2 S)] (Q = triphenylbenzylphosphonium, Ph 3 PBzl, or tetrabutylammonium, Bu 4 N) and [Pt(μ-Cl)Cl(Me 2 S)] 2 are reported. The compounds Q[PtCl 3 (Me 2 S)] were prepared by interaction of [PtCl 4 ] 2− with an excess of Me 2 S in non-aqueous media, reduction of [PtCl 5 (Me 2 S)] − with hydrazine sulfate, bridge-splitting reactions of (Ph 3 PBzl) 2 [Pt 2 (μ-Cl) 2 Cl 4 ] and [Pt(μ-Cl)Cl(Me 2 S)] 2 with two equivalents of Me 2 S and (Ph 3 PBzl)Cl, respectively, and substitution of dimethyl sulfide in trans -[PtCl 2 (Me 2 S) 2 ]. The [Pt(μ-Cl)Cl(Me 2 S)] 2 dimer was prepared via reaction of cis -[PtCl 2 (Me 2 S) 2 ] with two equivalents of silver nitrate followed by separation of AgCl(s) and addition of one equivalent of K 2 [PtCl 4 ]. The structure of (Ph 3 PBzl)[PtCl 3 (Me 2 S)] was determined by X-ray single crystal analysis. The compound crystallizes in the space group P 2 1 / n with a = 9.746(3), b = 19.511(4), c = 14.966(4) A, β = 100.43(2)°, V = 2799.0(9) A 3 and Z = 4.

Cis- and trans-influences in [PtCl2(SPh2)2].

Both cis- and trans-dichlorobis(diphenyl sulfide)platinum(II), [PtCl(2)(C(12)H(10)S)(2)], crystallize as mononuclear pseudo-square-planar complexes. In the cis compound, the Pt-Cl distances are 2.295 (2) and 2.319 (2) A, and the Pt-S distances are 2.280 (2) and 2.283 (2) A. In the trans compound, Pt is located on a centre of inversion and the Pt-Cl and Pt-S distances are 2.2786 (15) and 2.3002 (12) A, respectively.

cis-(R,S)-Bis(benzyl methyl sulfoxide)dichloroplatinum(II)

The coordination around the Pt atom in the title compound, [PtCl 2 (C 8 H 10 OS) 2 ], is pyramidally distorted from cis square-planar ; two chloride ions form Pt-Cl bonds of 2.310(3) and 2.307(3) A and two benzyl methyl sulfoxide groups form Pt-S bonds of 2.241(2) and 2.233 (2) A.

The trans Influence of the Silyl Ligand. Structure of trans-[PtCl(SiPh3)(PMe2Ph)2]

In the crystal structure of trans-chlorobis(dimethylphenylphosphine)(triphenylsilyl)platinum(II), [PtCl(C 18 H 15 Si)(C 8 H 11 P) 2 ], the Pt atom coordinates to one Si and one Cl atom, and to two P atoms in mutual trans positions. The coordination geometry is distorted square planar with distances Pt−Si 2.321 (2), Pt−Cl 2.465 (2) and Pt−P 2.282 (2) and 2.322 (2) A. The silyl ligand shows a very large trans influence on the Pt−Cl distance

[{PtCl(dmso)}2(μ-OH)2]

The crystal structure of di-μ-hydroxo-bis[chloro(dimethyl sulfoxide)platinum(II)], [Pt 2 Cl 2 (μ-OH) 2 (C 2 H 6 OS) 2 ], has been determined from X-ray intensity data. The compound contains a hydroxobridged dinuclear cis complex, i.e. the Cl atoms are in cis positions in [Cl(dmso)Pt(OH) 2 Pt(dmso)Cl]. Each Pt atom has pseudo square-planar coordination composed of one dmso molecule, one Cl atom and two hydroxo groups. The complexes are linked by a hydrogen-bond network parallel to the ab plane

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.