The Study of the Intramolecular Heavy Atom Effect in 9,10-Dichlorophenanthrene and 1,2,3,4-Tetrachloronaphthalene Using PMDR Techniques.

摘要

The heavy atom effect in triplet 9,10-dichlorophenanthrene and 1,2,3,4-tetrachloronaphthalene is investigated by PMDR techniques. As in the parent hydrocarbons, spin-orbit and spin-orbit vibronic mechanisms are invoked to explain the results. The relative radiative rates of the triplet zero-field levels are determined by static distortions of the chlorine atoms, while the intersystem crossing rates from S(1) are mainly governed by the enhancement of spin-orbit vibronic coupling via C-C1 out-of-plane modes that mix the relevant sigma, pi* and pi,pi* states. In both processes the top two levels tau(A) and tau(B) are more active, with Tau(B) the most favoured of the two. (Author)