Synthesis of Cp* iridium and rhodium complexes containing bidentate sp(2)-N-donor ligands and counter-anions [Cp*MCl3](-)

Abstract

Complexes of the type [Cp*MCl(N-N)][X] (M = Rh and Ir) have been synthesised, where N-N is a series of bidentate ligands with sp2 N-donors: bis(pyrazol-1-yl)methane (bpm), bis(1-methylimidazol-2-yl)methane (bim), bis(3,5-dimethylpyrazol-1-yl)methane (dmbpm), bis(1-methylimidazol-2-yl) ketone (bik), bis(2,4,6-trimethylphenylimino)acenapthene (mesBIAN), 2,4,6-trimethylphenylimino-(1-methyl-2-imidazolyl)methane (mesim-mim), and X = Cl-, BF4- and the unusual anion [Cp*MCl3]-. All of these complexes were synthesised by treatment of [Cp*MCl2]2 with 2 equivalents of ligand and were isolated as air stable solids. The solid-state structures of [Cp*MCl(bpm)][Cp*MCl3] (M = Rh and Ir) and [Cp*IrCl(bim)][Cp*IrCl3] have been determined by single-crystal X-ray diffraction analysis. All of the structures of the bimetallic species displayed a "piano stool" configuration about the both the anionic and cationic metal centre. The solid-state structures of the monometallic iridium species [Cp*IrCl(N-N)][BF4], where N-N = him, mesBIAN, and mesim-mim, were also determined using single-crystal X-ray diffraction analysis.