Singletndash;Triplet Transition Probabilities in Aromatic Hydrocarbons. I.1Ararr;3LaTransitions in Linear Polyacenes

摘要

A general expression for the transition moment of1Athinsp;rarr;thinsp;3Lain linear polyacenes is derived from the matrix elements of spinndash;orbit interaction betweenlpar;pgr;, pgr;rpar;andlpar;pgr;, sgr;rpar;states. Only onehyphen;center onehyphen;electron integrals are evaluated. The results indicate that the oscillator strength of this transition should decrease as the size of the linear polyacene increases. It is shown that this conclusion is most likely independent of the approximations employed. Interaction oflpar;pgr;, sgr;rpar;andlpar;pgr;, pgr;rpar;states quantitatively accounts for the main part of the oscillator strength of1Athinsp;rarr;thinsp;3Lain naphthalene.