BOUND EXCITED ELECTRONIC STATES OF ANIONS

Bound excited electronic states are observed in the anions of 7,7,8,8- tetracyanoquinodimethane (TCNQ), 2,5-dimethyl-N,N'-dicyanoquinodiimine (Me(2)-DCNQI), chloranil, and hexacyanobutadiene using electron photo detachment spectroscopy. Intensity dependence studies and two color ex periments are consistent with a two-photon detachment mechanism. A mec hanism is proposed to explain the observed photodetachment. The nature of the electronic state responsible for these excited states is discu ssed and other anions are suggested which should posses bound excited electronic states.