Dicarbonylrhodium(I) complexes of pyridine alcohol ligands and their catalytic carbonylation reaction

Abstract

Reaction of dimeric complex [Rh(CO) 2Cl] 2 with two molar equivalent of pyridine alcohol ligands (L) like 2-hydroxymethylpyridine ( a), 3-hydroxymethylpyridine ( b) and 4-hydroxymethylpyridine ( c) afford the rhodium(I) dicarbonyl complexes [Rh(CO) 2ClL]( 1a– c). The ligands are coordinated to the metal center through N-donor site. The complexes 1 undergo oxidative addition ( OA) reactions with various alkyl halides (RI) like CH 3I, C 2H 5I to produce Rh(III) complexes of the type [Rh(CO)(COR)IClL], where R = –CH 3( 2), –C 2H 5( 3). Kinetic data for the reaction of 1 with CH 3I indicate a first order reaction. The catalytic activity of the complexes 1 in the carbonylation of methanol was higher than that of the well known species [Rh(CO) 2I 2] −.