MANIFESTATION OF MOLECULAR CHROMOPHOR POLYMORPHISM IN DIFFUSE VIBRONIC SPECTRA

Abstract

For the case of homomorphic chromophores, the localization of the 0-0-transition n₀ is defined in a separate electronic transition cross-section spectrum s(n) by the extremum (¶j/¶n = 0) of the relation [s(n)/n]exp(mhn/2kT) = j(|n - n₀|) (“-“ and n > n₀ for absorption,“+” and n < n₀ for emission). It holds for the dipole Frank-Condon transition under conditions of thermal distribution on state sublevels. If the spectrum is formed by polymorphic chromophores, it constitutes of the sum of partial inputs of the separate chromophores with different n_i0. So, the area of the extremum is distorted, the extremum can even disappear and the distortions indicate chromofore polymorphism. Examples are given for the distortion from absorption, fluorescence, and phosphorescence spectra