A Versatile Starting Material: Substitution Reactions of Bis(acetato)bis(diethyl sulfide)platinum with Phosphines, Thiols, o-Hydroquinones and Dihydroxybenzoquinones

Abstract

The new compound cis-Pt(OAc)2(Et2S)2 has been prepared, and its use as a starting material in the synthesis of new complexes of platinum has been investigated. Substitution reactions with HO-OH or HO2-O2H (HO-OH = substituted catechol, HO2-O2H = substituted 2,5-dihydroxy-l,4-benzoquinone) gave the corresponding cw-Pt(O-O)(Et2S)2 and cw-Pt(O2-O2)(Et2S)2 compounds. In the case of O2-O2 = 2,5-dioxy-l,4-benzoquinone, a slow conversion to a yellow isomer formulated as trans-Pt2(μ-(O2-O2))2(Et2S)4 was observed. Reaction of K4[Pt2(μ-(O2-O2))2Cl4] (O2-O2 = 3,6-dichloro-2,5-dioxy-1,4-benzoquinone) with Et2S also gave trans-Pt2(μ-(O2-O2))2(Et2S)4. Reactions with ArSH (Ar = 4-MePh, 4-ClPh) first gave Pt(SAr)2(Et2S)2, which then slowly reacted further to form [Pt(SAr)2]n. Reactions with phosphines (PPh3, PPhMe2) led to displacement of the diethyl sulfide group(s) giving mono- and bis-substituted phosphine compounds. Iodine oxidation of the 1,2-quinone complexes Pt(O-O)(Et2S)2 resulted in the rapid formation of the free 1,2-quinone, whereas Pt-(SPhMe-4)2(Et2S)2 gave with iodine the free disulfide (4-MePhS-)2. In both cases PtI2(Et2S)2 was also formed. The configurations of the compounds described were derived from 1H NMR and IR data. © 1979, American Chemical Society. All rights reserved.