Electronic spectral shifts of the1Lb(agr;) excitation of aromatic moleculendash;rarehyphen;gas heteroclusters

摘要

Microscopic spectral shifts of the lowest spinhyphen;allowed weak1Lb(agr;) transitions of heteroclusters consisting of inerthyphen;gas atoms bound to naphthalene, phenanthrene, and pyrene were evaluated utilizing the multicenter monopole representation for the dispersive intermolecular interactions, in conjunction with a semiempirical scaling of the Huuml;ckel transition monopoles. These calculations predict that the spectral shift for the electronic origin of the1La(p) transition is higher by a numerical factor of 2ndash;4 than for the weak1Lb(agr;) transition, in accord with experiment. The semiempirical theory was applied for the calculation of cluster size and isomer structure dependence of the1Lb(agr;) spectral shifts in these heteroclusters.