Magnetic circular dichroism and anomalous fluorescence spectra of benz[ a]azulene and naphth[2,1- a]azulene

Abstract

Magnetic circular dichroism (MCD) and absorption spectra of benz[ a]azulene ( I) and naphth[2,1- a]azulene ( II) have been measured. The absorption spectra have been assigned by comparing the experimental results with the signs of Faraday B terms and transition energies computed by using the variable bond length SCF—π—MO CI method. The anomalous fluorescence spectra have been observed for I and II. From the assignment of the absorption spectra, it has been concluded that molecules I and II emit the fluorescence from the second excited singlet state.