Computer Resolution and Franck-Condon Analysis of the Electronic Absorption Spectrum of KMnO4in Water

Abstract

Abstract The electronic absorption spectrum of KMnO4 in water solution was analyzed. The spectral contour was resolved into component bands and then Franck-Condon approach was applied. In the investigated range of 13000–48000 cm−1 a presence of three structureless and of two vibronic strong bands was stated. The change in the Mn-O equilibrium bond length was found to be 10.5pm for 2e·1t1 transition (vibronic band about 18000cm−1) and to be 16pm for the 2e·3t2 transition (vibronic band about. 30000cm−1). The appropriate wavenumber of the vibrational mode in these excited electronic states was found to be 735cm−1 and about 780cm−1, respectively. The ground electronic state wavenumber of the totally symmetric vibrational mode was fitted to be equal to 828cm−1. Details of the proposed method of computer elaboration of electronic spectra with vibrational structure were discussed. Electronic absorption spectra of some inorganic comppunds consist of a number of strongly overlapped bands due to their vibronic str...