Far-ultraviolet solution spectroscopy of chloride ion

Abstract

The far-ultraviolet absorption spectra of chloride ion have been studied in a large variety of solvents and over a large range of temperatures. Solvents used include both blue- and red-shifting solvents for charge-transfer-to-solvent transitions, relative to water. New absorption bands have been observed, in addition to characterising those regarded as having been observed previously. For some solvents, measurements have been made down to 59 600 cm^–1. In contrast to the iodide and bromide spectra, only one band is found for each of the several states observed because of the small ²P doublet splitting. These bands, and also higher intensity electronic bands observed at higher energies, are correlated on the basis of solvent shifts, temperature sensitivities and oscillator strengths. The nature of the bands is discussed and tentative assignments suggested. Comparisons with bromide and iodide spectra are drawn.