Transition metal–carbon bonds. Part XXIII. Cationic iridium(I)–ethylene and 1,3-diolefin complexes

Abstract

trans-IrCl(CO)(PMe₂Ph)₂ reacts with ethylene in methanol in the presence of BPh₄^– to give [Ir(CO)(PMe₂Ph)₂(C₂H₄)₂]BPh₄. The ethylene may be displaced from this complex by PhC⋮CPh to give [Ir(CO)(PMe₂Ph)₂(PhC⋮CPh)]BPh₄ or by 2,3-dimethylbutadiene, to give [Ir(CO)(PMe₂Ph)₂(2,3-dimethylbutadiene)]BPh₄. [Ir(CO)(PMe₂Ph)₂(C₂H₄)₂]BPh₄ reacts with bromine to give the 2-bromoethyl complex IrBr₂(CH₂CH₂Br)(CO)(PMe₂Ph)₂ which, in turn, reacts with methanol to give IrBr₂(CH₂CH₂OMe)(CO)(PMe₂Ph)₂. trans-IrCl(CO)(PMe₂Ph)₂ reacts with butadiene or isoprene in methanol to give cationic iridium–diolefin complexes of type [Ir(CO)(PMe₂Ph)₂(diolefin)]⁺, isolated as the tetraphenylborate or other salts. Other reactions are discussed. I.r. and n.m.r. data are given.