cis‐trans Isomerization of bis(Dialkylsulfide)Dihaloplatinum(II) Complexes in Solution

Abstract

Summavy. The equilibrium encrgetics and the kinetics of cis-trans isomerization of some bis(dialkylsulfidc)dihaloplatinum(II) complexes have been examined by lH-NMR. spectroscopy. The isomers are stable in chloroform but each form isomerizes to an equilibrium mixture when free dialkylsulfide is added. The cis to trans process is endothermic and the position of the equilibrium is markedly depcndent on the nature of the donor atoms and of the solvent. Thc rate of isomcrization of Pt(Me2S),Cl, is first order in complex and in Me& The isomerization proceeds by a double displacement mechanism as i t isshown that the tris(dimethylsulfide)chloroplatinum(II) cation is an isolable intermediate of the reaction. When free Me,S is added to tvans-Pd(Me,S),Cl,, isomerization does not occur and onc observes instead a fast ligand exchange. Its mechanism is the usual associative one for substitutions in squarc planar d*-complexes.

Hexaplatinum Clusters with Carbonyl and Diphosphine Ligands and the Trapping of Mercury(0) and Thallium(I)

“…All reactions were carried out under N 2 atmosphere using Schlenk techniques. The compound [PtCl 2 (Me 2 S) 2 ] was prepared by the literature method . IR spectra were recorded by using a Perkin-Elmer 2000 spectrometer; the NMR spectra were recorded by using a Varian Gemini-300 spectrometer.…”

Structural characterization of platinum(II)–methionine complexes in aqueous solution

“…The discovery that the [PtCl,]' -complex ion binds preferably to the methionine (Met) residues in proteins ' aroused an interest in platinum(l1)-methionine compounds. However, there have been few reports on the structural characterization of platinum- (11) complexes containing methionine and chloride ligand~.,-~ The chelate [PtCl,(Met)] was synthesised, isolated and characterized by the use of IR and NMR spectroscopy. Two platinum(i1) complexes containing N-acetylmethionine ligand were also in~estigated.…”

Platinum(II) complexes with ligands (RO)2PCH2P(OR)2(R = Me, Et, Ph, or C6H4Me-4); crystal structure of cis,cis-[Pt2Me4{µ-(EtO)2PCH2P(OEt)2}2]

“…in CDCl,: dtopm, 'H, 6 2. 28 To a stirred solution of trans-[PtI,(SMe,),] (0.06 g, 0.11 mmol) in dry CH2C12 (10 cm3) was added an equimolar amount of deopm in dry diethyl ether (1 cm3) and the mixture stirred for ca. 1 h. A yellow solid was isolated after adding pentane (20 cm3) and evaporation under vacuum.…”