REACTIONS OF ATOMIC METAL-IONS WITH ALKYL-HALIDES AND ALCOHOLS IN THE GAS-PHASE

The chemistry of Li+, Na+, Fe+, Co+, and Ni+ with alkyl halides and alcohols in the gas phase as elucidated by ion cyclotron resonance spectroscopy is described. The alkali metal ions induce dehydrohalogenation and dehydration of alkyl halides and alcohols, respectively. Reactivity of R-X decreases with increasing D(R+-X-) indicating a mechanism involving charge generation at the carbon. A potential energy surface with a barrier associated with such a charge generation is proposed and discussed quantitatively. From halide transfer reactions of RX to alkali metal ions it is deduced that ΔHr°298( 1-adamantyl cation) = 160.7 ± 3.0kcal/mol and ΔHr°298(C7H7+) ≤215.1 ± 3.0kcal/mol. Fe+, Co+, and Ni+ formed by electron impact on Fe(CO)5, Co(NO)(CO)3, and Ni(CO)4, respectively, dehydrate alcohols and dehydrohalogenate alkyl halides by a mechanism completely different from the alkali metal ion reactions. Oxidative addition of M+ to RX giving RMX+ is postulated. In some cases MR+ and MX+ products are observed. Limits on several (M+-X) bond strengths are deduced. It is deduced from observed reactions that the proton affinities of Fe and FeO are ≤203 and ≥227 kcal/mol, respectively. Reactions with the alcohols and alkyl halides of ions other than M+ formed by electron impact on the carbonyls are also described. Reactions with the neutral metal carbonyls of a number of organic ions formed from the alky! halides and alcohols are described. © 1979, American Chemical Society. All rights reserved.