Theoretical Study of the Electronic Excited States of Tetracyanoethylene and Its Radical Anion

摘要

The low-lying electronic states of tetracyanoethylene(TCNE)and its radical anion were studied using multiconfigurational second-order perturbation theory(CASPT2)and extended atomic natural orbital(ANO)basis sets.The results obtained yield a full interpretation of the electronic absorption spectra,explain the spectral changes undergone upon reduction,give support to the occurrence of a bound excited state for the anionic species,and provide valuable information for the rationalization of the experimental data obtained with electron transmission spectroscopy.