Theoretical Foundations of the Classification of Molecules by Luminescence Spectra

The relationship between the luminescence spectra and the structure of aromatic molecules is discussed theoretically. Various semi-empirical methods of calculating the electronic states of polyatomic molecules are briefly described. The orbitals involved in the electronic transitions and states and the effect of molecular structure and other factors on the energy of the states are considered. The spin–orbit interaction of molecular states is discussed, and radiative transitions in molecules are examined in relation to the nature of the molecule. Modern views on the nature of the conversion processes are outlined, and the variation of their rate with the type of transition and with the energy spectrum and structure of the molecule is analysed. Molecules are classified into five types according to their luminescence spectra, and a justification of this classification is given.
The bibliography includes 154 references.