Abstract: The geometric configurations of tris{5-[(2'-fluoro-4'-bromo-benzylidene)-amino]-quinolin-8-ol} aluminum(AlA₃) and 5-[(2'-fluoro-4'-bromo-benzylidene)-amino]-quinolin-8-ol were optimized by PBE0 method. The electronic spectra of the complex and ligand were calculated by TDDFT method. It is indicated from the calculation that: (1) for the larger Pauli repulsion of ligand, the interaction energy of AlA₃ is weaker than that of tris(8-hydroxy quinolinato)aluminum(AlQ₃);(2) the maximal absorption wavelength of AlA₃, which is assigned to charge transfer between different quinolin-8-ol, is the characteristic band of AlQ₃ analogue. The decrease of LUMO energy results in a red shift in electronic absorption spectrum compared to that of AlQ₃;(3) the 269 nm band is assigned to charge transfer from CN group to quinolin-8-ol.

Key words: Tris{5-[(2’-fluoro-4’-bromo-benzylidene)-amino]-quinolin-8-ol}aluminum, Quantum chemistry method, Electronic spectrum, Binding energy