Germyl–iridium complexes

Abstract

Germanes, R₃GeH (R = Me, Et, or Cl) react with (Ph₃P)₂Ir(CO)CI to form six-co-ordinate dihydrido-complexes, (Ph₃P)₂Ir(CO)(H)₂GeR₃(IV); their stereochemistry in solution has been elucidated from their ¹H n.m.r. and i.r. spectra. Triphenylgermane behaves differently forming the five-co-ordinate complex, Ph₃PIr(CO)(H)(CI)-GePh₃(XII). The Ge–Ir bond in (IV)(R = Me or Et) is cleaved at 150° with regeneration of the germane. It is also cleaved by oxygen, C₂H₄Br₂, I₂, and HCI, H₂, and HgCl₂. Triphenylphosphine in (IV) may be replaced by Et₃P or (Ph₂PCH₂)₂. Ethylene is hydrogenated by (IV) to yield the iridium(I) complex, (Ph₃P)₂Ir(CO)GeR₃(XI) which is reconverted into (IV) by H₂. Trimethylgermane and (Et₃P)₂Ir(CO)CI form H₂, Me₆Ge₂, and (Et₃P)₂Ir(CO)(H)₂CI. Bistrimethylgermylmercury and (Ph₃P)₂Ir(CO)CI react to give the germylmercury complex (Ph₃P)₂Ir(CO)·Hg·GeMe₃ together with mercury and trimethylchlorogermane.