Special features of absorption and fluorescence spectra of immunoactive 8-azasteroids

Biologically active molecules of 8-azagon-12,17-dion fluoresce in solvents of various natures, in the crystalline phase, and under conditions of high- temperature vapor. Characteristics of absorption and fluorescence of these molecules in aprotic acetonitrile are studied in detail. Absorption observe d in the region of 250-400 nm is associated with transitions of the types p i --> pi* and n --> pi*. Fluorescence excitation spectra demonstrated depen dence of emission detected on the wavelength. Experimental data are analyze d within the framework of concepts of the multicentered nature of molecular systems on the basis of the model of electronic mesomeric tautomerism. (C) 2001 MAIK "Nauka/Interperiodica".