On the Problem of Multiple Minima on the S2 Excited Potential Energy Surface of Benzene: A Restricted Active Space Self Consistent Field Study

Abstract

Application of the Restricted Active Space Self‐Consistent Field Theory on the S2 excited state potential energy surface of benzene shows the existence of three minima. Of these, the first one is planar with a D6h molecular point group, while the other two have a boat type structure with an approximate C2v symmetry. All three minima have a biradicaloid structure and constitute potential candidates for new photochemical pathways on the S2 surface. A common S2/S1 Conical Intersection, which is accessible from all three S2 minima has been found which decays to the S1 potential energy surface (PES) giving benzene S1 minimum as the only photoproduct.

Photochemical mechanistic study of hexafluorobenzene involving the low-lying states

“…27 Recently, three S 2 minima have been reported on the S 2 excited potential energy surface of benzene: two boat-type minima and one planar minimum, respectively. 28 In the beginning, we also tried to locate the boat-type minimum for the S 2 state of HFB. However, the boat-type minimum was not found.…”