Luminescence of aromatic molecules is vary important in organolumines-cence. In this paper

it is simply introduced to calculate the absorption and fluorescence spectra of aromatic molecules by using quantum chemistry methods. Relationships between the luminescence behaviour and the structure of aromatic molecules are described Energy transfer and migration in organic systems are discussed in detail. The spectrum investigation of aromatic molecules using quantum chemistry methods involves Huckel’s molecule orbital theory (LCAO-MO)

Platt’s perimeter free-electron orbital calculations (PFEO) and Pariser-Parr-Pople calculations (PPP) Luminescence behaviour of aromatic molecules is closely related to their structure such as bonds

planeness

rigidity and size of molecules and substituted aromatic compounds Energy transfer and migration in organic systems involve the radiation transfer

dipole-dipole resonance transfer

exciton diffusion

diffusion-controll process and electron transfer process. It is suggested recently that the process of excimer formation and dissociation should be also a kind of energy transfer.