Reactions of low-valent metal complexes with fluorocarbons. Part XIV. Hexafluoroisopropylideneamine-nickel and -platinum complexes

Abstract

Ethylenebis(triphenylphosphine)nickel reacts with the imine hexafluoroisopropylideneamine or the N-methylamine to form stable crystalline complexes [Ni(Ph₃P)₂{(CF₃)₂CNR}](R = H or Me). Reaction of bis(cycloocta-1,5-diene)nickel with N-methylhexafluoroisopropylideneamine affords [Ni(1,5-C₈H₁₂){(CF₃)₂CNMe}], which on treatment with triphenylphosphine, methyldiphenylphosphine, bipyridyl, or 1,2-bis(dimethylphosphino)-ethane, gives stable imine complexes, cyclo-octa-1,5-diene being displaced. In contrast, trimethyl phosphite displaces both the diene and the imine from [Ni(1,5-C₈H₁₂){(CF₃)₂CNMe}].

The analogous platinum complexes [Pt(Ph₃P)₂{(CF₃)₂CNR}](R = H or Me) are obtained by reaction of trans-stilbenebis(triphenylphosphine)platinum with the corresponding imine. Trifluoroacetic acid reacts with [Pt(Ph₃P)₂-{(CF₃)₂CNH}] to form the platinum(IV) complex [Pt(Ph₃P)₂{(CF₃)₂CNH}(CF₃CO₂)₂], whereas a similar reaction with the N-methyl analogue gives [Pt(Ph₃P)₂(H){(CF₃)₂CNMe}(CF₃CO₂)]. Treatment of [Pt(Ph₃P)₂{(CF₃)₂CNH}] with hexafluoroacetone leads to a ring-expansion reaction and the formation of a five-membered heterocyclic ring compound. Hexafluoroacetone displaces N-methylhexafluoroisopropylideneamine from [Pt(Ph₃P)₂{(CF₃)₂-CNMe}] to give the known complex [Pt(Ph₃P)₂{(CF₃)₂CO}].