Dicarbonylrhodium(I) complexes of aminophenols and their catalytic carbonylation reaction

The complexes [Rh(CO) 2 ClL]( 1 ), where L = 2‐aminophenol ( a ), 3‐aminophenol ( b ) and 4‐aminophenol ( c ), have been synthesized and characterized. The ligands are coordinated to the metal centre through an N‐donor site. The complexes 1 undergo oxidative addition ( OA ) reactions with various alkyl halides ( RX ) like CH 3 I, C 2 H 5 I and C 6 H 5 CH 2 Cl to produce Rh(III) complexes of the type [Rh(CO)(COR)XClL], where R = CH 3 ( 2 ), C 2 H 5 ( 3 ), X = I; R = C 6 H 5 CH 2 and X = Cl ( 4 ). The OA reaction with CH 3 I follows a two‐stage kinetics and shows the order of reactivity as 1b > 1c > 1a . The minimum energy structure and Fukui function values of the complexes 1a–1c were calculated theoretically using a DND basis set with the help of Dmol 3 program to substantiate the observed local reactivity trend. The catalytic activity of the complexes 1 in carbonylation of methanol, in general, is higher (TON 1189–1456) than the species [Rh(CO) 2 I 2 ] − (TON 1159). Copyright © 2007 John Wiley & Sons, Ltd.