Carbene complexes of iridium, rhodium, manganese, chromium, and iron containing thiazolidinylidene and pyridinylidene ligands

Abstract

New carbene complexes of Ir^I, Rh^I, Mn^I, Cr⁰, and Fe⁰ have been prepared by reactions of the appropriate carbonylmetal anions with N-methyl- and N-ethyl-2-chloro-4-methylthiazolium tetrafluoroborate and N-methyl-2-chloropyridinium tetrafluoroborate. The anions [Ir(CO)₃PPh₃]^–, [Rh(CO)₂(PPh₃)₂]^–, and [Mn(CO)₅]^– afford cationic carbene complexes, whereas [Cr(CO)₅]^2– and [Fe(CO)₄]^2– yield neutral carbene complexes. Treatment of [Mn(CO)₅{[graphic omitted]}][BF₄] with iodide ion gives a neutral complex [cis-Mnl(CO)₄{[graphic omitted]}].

The cation [Ir(CO){[graphic omitted]}(PPh₃)₂]⁺ reacts with hydrogen to give [IrH₂(CO){[graphic omitted]}(PPh₃)₂]⁺. The cation also reacts oxidatively to give Ir^III complexes with HCl, Cl₂, and I₂. Lithium chloride or bromide reacts to give [IrH(X)(CO){[graphic omitted]}(PPh₃)₂][BF₄](X = Cl or Br), whereas [Ir(CO){[graphic omitted]H}(PPh₃)₂][BF₄] affords the neutral Ir^III species [IrCl₃{[graphic omitted]H}(PPh₃)₂]. Methyl iodide reacts with [Ir(CO){[graphic omitted]}(PPh₃)₂][BF₄] to give [Irl₂Me(CO){[graphic omitted]}(PPh₃)].

Some spectroscopic properties of the new complexes are reported.