Transition metal complexes with terminal or bridging imidato(1–) ligands. X-Ray crystal structures of trans-[Ir(CO)(NCOC2F4CO)(PPh3)2] and [{Pd(o-C6H4CHNPh)(µ-NCOC2H4CO)}2]·CH2Cl2, spectroscopic studies of [Mn(CO)5(NCOC2H4CO)], and the nature of the metal–nitrogen bond

Abstract

The reaction of [Mn(CO)₅Br] with the thallium(I) salt of succinimide yields the novel succinimidato(1–) complex [Mn(CO)₅([graphic omitted]O)]. The imide-derived ligand is found to behave as a pseudo-halogen in terms of its σ-acceptor and π-donor properties by ‘Graham’ analysis of i.r. spectroscopic data. Mononuclear arylpalladium complexes, trans-[Pd(Ph)(im)(PPh₃)₂][im =Imidato(1–) ligand], and related carbonyl–rhodium and –iridium complexes, trans-[M (CO)(im)(PPh₃)₂], may be synthesised by reaction of the corresponding chloro-complexes with succinimide, phthalimide, or tetrafluorosuccinimide. The structure of trans-[Ir(CO)([graphic omitted]O)(PPh₃)₂] has been established crystallographically (Ir–N 2.09 Å). Binuclear arylpalladium complexes containing halide or acetate bridges react with imides in the presence of base to give complexes in which the Imidato(1–) ligand adopts a novel bridging co-ordination mode, via nitrogen and one of the carbonyl oxygens. The structure of one complex of this type, [{Pd(o-C₆H₄CHNPh)(µ-[graphic omitted]O)}₂]·CH₂Cl₂, has been confirmed crystallographically.