Chemical applications of laser narrowing spectroscopy

Abstract

A brief outline of spectral hole-burning and fluorescence and excitation line narrowing spectroscopies is presented. These techniques overcome inhomogeneous broadening of optical spectra and when appropriately directed, have the capacity of being able to determine unambiguously the nature of electronic excitations and photophysical processes. A number of examples of interest in chemical spectroscopy are presented. Included are the direct determination of the pure spin triplet nature and zero field splittings of 3 π– π ∗ , luminescent states and excitation dynamics and intramolecular excitation transfer processes in 3MLCT states in d 6 di-imine complexes and recent work on argon matrix isolated metal phthalocyanines. Important concepts include energy level correlations and what we have termed nanoheterogeneity within distributions of chromophores. These phenomena have important consequences towards the understanding of many species in amorphous environments. © 1997 Elsevier Science B.V.