Electronic structure and nature of the bands in electronic absorption spectra of stable phenoxyl radicals of indophenoxyl and galvinoxyl

On the basis of results from quantum chemical calculations, made using the CNDO/S approximation method and taking into account configurational interaction, it has been shown that the first long-wave and subsequently more intense bands in the electronic absorption spectra of the phenoxyl radicals indophenoxyl and galvinoxyl are due to ππ* electron transfers. The bands related to the pπ* electron transfers of unshared p-electron pairs of oxygen and nitrogen atoms are located between them. It is suggested that displacement of the spectrum bands into the red region in transferring from the indophenoxyl to the galvinoxyl radical is caused by a reduction of the electron acceptor capacity of the bridging atom between the phenoxyl groups of the radical