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".