Concerning the spectra and solvation process of electrons in liquid butanols

Open Access
Publisher Website
Google Scholar
Abstract
The optical absorption spectra of electrons injected into the isomeric butanols settle into that of the equilibrium solvated state at rates that decrease in the order 1-butanol > isobutyl alcohol > 2-butanol at a given temperature. The relative rates reflect the dipolar reorientation times in the liquids. The Arrhenius temperature coefficients of the rates of spectral changes are ∼30 kJ/mol. The distribution of dipolar reorientation times overlaps that of geminate reaction times of the charges in an irradiated alcohol, so a significant fraction of the electrons undergoes geminate reaction before they are able to become fully solvated. At T < 200 K the fraction increases with decreasing temperature. The concurrence of the solvation process and geminate reaction implies that the former involves, at least in part, electron migration from shallower to deeper traps.There is an indication of structure in the absorption band at low temperatures and short times. The infrared peak converts to one with a maximum at ∼780 nm. The latter slides gradually into the shape of the spectrum of the equilibrium solvated state.For the spectra of the equilibrium solvated state, the energies at the absorption maxima are given by Eεmax (eV) = 3.10 − 0.0038T in isobutyl alcohol and 2.93 − 0.00447 in 2-butanol, between 170 and 300 K. The respective band widths at half heights are 1.53 ± 0.04 and 1.59 ± 0.04 eV, independent of temperature within an uncertainty of 1 meV/K.

This publication has 0 references indexed in Scilit: