Reactivity of main-group–transition-metal bonds. Part I. Kinetics of lodination of tricarbonyl(η-cyclopentadienyl)(trimethylstannyl)-molybdenum and -tungsten, dicarbonyl(η-cyclopentadienyl)(trimethylstannyl)iron, and pentacarbonyl(trimethylstannyl)manganese

Abstract

The kinetics of cleavage of the tin–transition-metal bond in [Me₃SnMo(CO)₃(cp)], [Me₃SnW(CO)₃(cp)], [Me₃SnMn(CO)₅], and [Me₃SnFe(CO)₂(cp)] by iodine in carbon tetrachloride have been studied (cp =η-cyclopentadienyl). The reaction is an electrophilic substitution at the metal–metal bond. The relative rates for the above four compounds are M = Fe > Mo ≈ W ≫ Mn. The simplicity of the kinetics for the iodination of these compounds probably masks the complexity of the reaction, and schemes involving charge-transfer complexes and chemical intermediates are proposed.