Binuclear pyrazolato-bridged organoplatinum(II) complexes: Synthesis and characterization

Abstract

Binuclear organoplatinum(II) complexes of the type [pt 2Ar 2(μ-NN) 2(PR 3) 2] [Ar = Ph, C 6H 4Me- 4 (tol), C 4H 3S-2 (th); NNH = pyrazole (pzH), 3,5-dimethylpyrazole (3,5-tmpzH), 3,4,5-trimethylpyrazole (3,4,5-tmpzH); PR 3 = PBu 3, PMe 2Ph, PMePh) 2] were prepared by reaction of [pt 2Ar 2(μ-Cl) 2(PR 3) 2] with NNH and sodium hydroxide in methanol. The reaction of [pt 2 tol 2(μ-3,5-dmpz) 2(PMe 2Ph) 2] with isopropylmerecaptan gave a thiolato-biridged complex [pt 2tol 2(μ-S iPr) 2(PMe 2Ph) 2]. All these complexes were characterized by elemental analyses and NMR ( 1H and 31 P) spectroscopy. Some of the complexes could be isolated in the trans or cis form, others as a mixture of cis and trans isomers. Isomerization reactions have been studied by 31P NMR spectroscopy.