Assignments of the electronic transitions in the methoxy-substituted benzenediazonium cations

Abstract

The visible-ultraviolet absorption spectra of benzenediazonium, 2-, 3-, 4-methoxybenzenediazonium, 2,4-, 2,5-, 2,6-, 3,4-dimethoxybenzenediazonium, and 2,3,5-, 2,4,5-, 2,4,6-, 3,4,5-trimethoxybenzenediazonium cations were measured in the 200-450-mμ region. The assignments of the electronic transitions of these materials were made possible through the use of molecular orbital theory. An excellent quantitative correlation between the calculated and observed values of the transition energies is obtained. The assignments of the 1La and 1Lb transitions are in qualitative agreement with those previously assigned for other "strongly substituted" benzenes.