Rhodium(I) carbonyl complexes [Rh(CO)(2)CIL] (1) where L = Py-2-CHO (a), Py-3-CHO (b) and Py-4-CHO (c) have been synthesized and characterized by elemental analyses, IR, H-1 and C-13 NMR spectroscopy. The complexes I undergo oxidative addition reactions with different types of electrophiles such as CH3I, C2H5I, C6H5CH2Cl and I-2 to yield [Rh(CO)(COCH3)ClIL] (2), [Rh(CO)(COC2H5)ClIL] (3), [Rh(CO)(COCH2C6H5)Cl2L] (4) and [Rh(CO)CII2L] (5) complexes, respectively. The kinetic study of the complexes 1 with CH3I reveals a two-stage kinetics and the second-stage reactions are faster than that of the first stage by about 80-100 times. The rate of reaction of la is higher than that of 1b and 1c. The catalytic activity of complexes 1 in carbonylation of methanol, in general, is higher (TON 800 - 1250) than that of the well-known species [Rh(CO)(2)I-2](-) (TON 650). (C) 2004 Elsevier B.V. All rights reserved.