Dicarbonylrhodium(I) complexes of aminophenols and their catalytic carbonylation reaction |
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Authors: | Manab Sharma Bhaskar J. Sarmah Pradip Bhattacharyya Ramesh C. Deka Dipak K. Dutta |
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Affiliation: | 1. Material Science Division, Regional Research Laboratory (CSIR), Jorhat‐785 006, Assam, India;2. Department of Chemistry, Gauhati University, Guwahati, Assam, India;3. Department of Chemical Sciences, Tezpur University, Tezpur, Assam, India |
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Abstract: | The 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. |
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Keywords: | rhodium complexes aminophenol oxidative addition carbonylation of alcohols DFT calculations |
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