Paramagnetic organometallic molecules. XIV. Ion-pair and steric effects in dissociative electron transfer reactions of metal cluster carbonyl radical anions

Abstract

An investigation of electron attachment reactions of cluster metal carbonyls is presented. In general, alkyl and organometallic halides react rapidly with metal carbonyl cluster radical anions at ambient temperatures to give the neutral cluster molecule. Halide ion and alkyl or organometallic radicals are also produced, which indicate that these are dissociative electron attachment reactions analogous to those of organic radical anions. The rate of dissociative electron attachment in reactions of PhCCo₃(CO)₉- was found to depend on the R-X bond energy, the size of the alkyl group and the nature of the counter-ion. In particular, (Ph₃P)₂N⁺ retarded some electron transfer reactions to the extent that the bimolecular decay of PhCCo₃(CO)₉^- effectively competed with the electron transfer process in determining the reaction path.