Excited electronic states and generation in series of complex polyatomic molecules

The photophysical properties of some new and also some known complex organic molecules which emit in the wavelength interval 340–410 nm have been studied in a wide range of organic solvents. Specifically, these molecules are based on phenyl-, furyl-, and thienyl-oxazoles and oxadiazoles. Density-matrix methods are used to study the properties of a broad spectrum of excited singlet and triplet electronic states. There are relationships among the structure, fluorescence spectra, and emission properties of the complex molecules forming a quasihomologous series. The method of a priori structural modeling of active complex molecules is useful for achieving quantum-mechanical control over the properties of the excited states and the transitions.