Luminescent organic/organometallic compounds have attracted much attention recently because of their applications to electroluminescent display. The most well-known example of such chelate compounds is Alq₃, q＝deprotonated 8-hydroxyquinoline, a green emitter and an electron transporter in organic EL devices. The structures of zinc complex with 8-thiolquinoline anion [Zn(tq)₂] and its derivatives were optimized in the ground state using ab initio HF and B3LYP methods, and absorption spectra based on the above structures were obtained by the time-dependent density functional theory (TD-DFT) by the B3LYP method with the 6-31＋G(d) basis set. At the same time, the molecular structure of the first singlet excited state for Zn(tq)₂ and its derivatives was optimized by CIS/6-31G(d), and the EL peak could be obtained by the emission spectrum with TD-B3LYP/6-31G(d) method. The calculated results indicated that the luminescence originates from the electronic transition from the thiophenol ring to the pyridine ring. The calculated results of absorption spectrum and emission spectrum for zinc complex with 8-thiolquinoline anion and its derivatives have good agreement with the experimental data. All compounds are excellent electron-transporting materials, luminescence wave bands of which can be tuned by different metals and substituent on the ligand of 8-thiolquinoline anion.

Key words: zinc complex with 8-thiolquinoline anion, absorption spectrum, emission spectrum, time-dependent density functional theory