The Chemistry of Solvated Distonic Ions: Preparation, Isomerization, and Fragmentation

Abstract

It has been shown that solvated distonic ions can be prepared by selected collision-induced radical removal from the proton-bound dimer of appropriate molecules. The α- and β-distonic ethanol ions solvated by methanol or ethanol, [CH3•CHOH2+/ROH] and [•CH2CH2OH2+/ROH] (ROH = CH3OH and C2H5OH), have been prepared by selected loss of a designated radical from the proton-bound dimer of labeled alcohols, and their reactions studied in the metastable ion time frame. It is found that isomerization of the α-distonic ion to its conventional structure can be catalyzed by both methanol and ethanol, such that the energy barrier to this process is reduced to 25 ± 2 kcal mol-1, lower than that in the uncatalyzed reaction by 10 kcal mo1-1. The β-distonic ions do not isomerize to either the α-form or the conventional form when solvated by the alcohol molecule, and their fragmentation is dominated by water loss, similar to the isolated ion.