Zur Photochromie der Dehydrodianthrone. PPP-Rechnungen

Abstract

The spectral features and related parameters of Dehydrodianthrone in the ground, the photochromic and the triplet state have been calculated with the aid of the Pariser-Parr-Pople method. The calculated S₀ → S_n absorption spectra and the T₁ → T_n absorption spectra of the parent form are in good agreement with the experimental findings. Two reasonable structures for the photochromic form of this molecule have also been treated theoretically. The results suggest that a valence-isomeric form is the most probable structure of the green photochromic form.