A π-bonded trifluoroacetonitrile complex of platinum(0)

Abstract

Trifluoroacetonitrile displaces trans-stilbene from Pt(trans-stilbene)(PPh₃)₂ to give Pt(π-CF₃CN)(PPh₃)₂, (I). The trifluoroacetonitrile ligand in (I) is labile and is displaced by diphenylacetylene and carbon monoxide to give Pt(PhCCPh)(PPh₃)₂ and Pt₃(CO)₃(PPh₃)₄ respectively. Other displacement reactions indicate that the complexes Pt(L)(PPh₃)₂ decrease in stability in the order of ligands (L), (CF₃)₂CO > PhCCPh > CF₃CN > CF₂CH₂ > trans-PhCHCHPh. In addition to Pt{(CF₃)₂CO}(PPh₃)₂, a five-membered ring complex (Ph₃P)₂P[graphic omitted] may also be isolated from the reaction of (I) with hexafluoroacetone. Treatment of (I) with trifluoroacetic acid gives a mixture of trans-PtH(OCOCF₃)(PPh₃)₂ and trans-Pt(OCOCF₃)-{C(CF₃)NH}(PPh₃)₂.