A quantum chemical study of the cyclic oxocarbon dianions C nO n−2 ( n = 3, 4, 5 and 6) : II. Electronically excited states

Abstract

The electronic spectra of the title compounds have been studied by the ab-initio SCF-CI and CNDO/S methods. Excited energies for the singlet—singlet transitions have been calculated and compared with the available experimental values and with earlier calculated data. The energies for the singlet—triplet transitions for the deltate and squarate dianions are also reported.