STRUCTURE AND FORMATION OF METHYLLITHIUM IONIC FRAGMENTS

Properties of the methyllithium species Li4(CH3)3+, Li4(CH3)2+, Li4CH3+, Li2CH3+, LiCH3+, and Li2(CH32 have been probed by the application of an ab initio computational procedure. These lithium cluster species are the methyl analog of the products observed experimentally to result from the fragmentation of ethyllithium and t-butyllithium. The procudure was used to determine the optimum geometry for each species. The total energy calculated for favored conformations of the subject fragments was used to estimate that δE's for possible paths through which the optically excited parent, Li4(CH3)4, could dissociate. The stable ions found and their modes of formation were compared to photofragments formed by dissociative ionization of Li4[C(CH3)3]4 reported recently. © 1979.