Solvated electrons in alcohol-alkane and alcohol-amine solutions

Abstract

The absorption spectrum of the solvated electron formed by pulse radiolysis of solutions of ethanol in 3-methylpentane, 2,2-dimethylbutane, and neopentane is unaffected by the presence of these alkanes above a few mole per cent of ethanol at room temperature. Above about 20 mol% solvated electron yields per unit of absorbed energy increase in the same order as the radiolytic free-ion yields of the pure alkanes. Below about 10 mol% this order is reversed and the half-time for decay of the solvated electron at constant solution composition also decreases with increasing extent of chain branching in the alkane constituent. Similarly, the solvated electron yield in dilute solutions of methanol, ethanol, and cyclohexanol in neopentane decreases with increasing hydrocarbon character of the alcohol constituent. ln ethanol- ethylenediamine solutions the amine is, to the contrary, the dominant solvating agent. These observations are discussed in the context of preferential solvation of excess electrons by microscopic aggregates of alcohol molecules and destabilization of these aggregates by alkanes and ethylenediamine. (auth)