Cyclometalated rhodium(III) and iridium(III) complexes containing amino acids as N,O-chelates

The synthesis of bis-cyclometalated aminocarboxylato complexes [M(alpha-aminocarboxylato)(ptpy)(2)] (M = Rh, 3, 4, 5; M = Ir, 6, 7, 8), ptpy = 2-(p-tolyl)pyridinato; aminocarboxylato = glycinato, L-alaninato, L-prolinato) from [{M(l-Cl)(ptpy) 2} 2] (M = Rh, 1; M = Ir, 2) is described. The molecular structure of [Ir(L-alaninato)(ptpy)(2)] (7) was confirmed by a single-crystal X-ray diffraction study. Compound 7 crystallized from methanol-iso-hexane in the space group P2(1). For 7 the two diastereoisomers Delta(Ir), S-C and Lambda(Ir), S-C were found crystallizing twice per unit. Absorption and emission spectra were recorded. The rhodium compounds are weak yellow-green and the iridium species strong green emitters. (C) 2011 Elsevier B. V. All rights reserved.