FREQUENCIES OF MULTIPLE CHARGE-TRANSFER BANDS OF METHIODIDES OF SOME NITROGEN HETERO-AROMATICS

The multiple charge-transfer (CT) absorption and emission bands of the methiodides of the diazines, quinaldene, and acridine have been studied. The frequency of the first charge-transfer band correlates well with calculated electron affinity of the cation and ionization potential of the anion, if interaction with the solvent is taken care of. The observed variation in the separation of the two CT bands of solution spectra can be explained if the interaction of the 2P1/2 and 2P3/2 states of the I atom with the organic part in the excited CT state is taken into account. The multiplicity in maxima in emission spectra needs further investigation. © 1979 American Chemical Society.