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

Abstract

AbstractThe complexes [Rh(CO)2ClL](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 CH3I, C2H5I and C6H5CH2Cl to produce Rh(III) complexes of the type [Rh(CO)(COR)XClL], where R = CH3(2), C2H5(3), X = I; R = C6H5CH2 and X = Cl (4). The OA reaction with CH3I 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 Dmol3 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)2I2]− (TON 1159). Copyright © 2007 John Wiley & Sons, Ltd.