ELECTRONIC ABSORPTION SPECTRA OF SUBSTITUTED ANTHRAQUINONES AND THEIR SIMULATIONUSING ZINDO/S METHOD
Z. Marković, N. Manojlović, S. Zlatanović
Abstract
Electronic absorption spectra of chrysophanol (1,8-dihydroxy-3-methylanthracene-9,10-dione),
physcion (1,8-dihydroxy-3-methoxy-6-methylanthracene-9,10-dione) and emodin (1,3,8-
trihydroxy-6-methylanthracene-9,10-dione) were investigated. Molecular geometries of the
substituted anthraquinones in the ground state were optimized using semiempirical AM1
method without imposing any symmetry constrains. The ground state geometries of all the
molecular systems were found to be planar. For interpretation of the spectra, ZINDO/S-CI
investigation employing singly excited configuration using the completely optimized
geometries was carried out. Such calculations on the electronic spectra of chrysophanol,
physcion, and emodin were carried out for the first time. On the basis of these investigations,
the assignments of the spectra were successfully predicted.
