Theoretical Study On Metal Complexes Containing Organic Ligands For Luminescent Materials

Applying the quantum chemistry methods,these three systems have been systematically studied: (1) 8-hydroxyquinoline Platinum complexes, (2) unsymmetrical organometallic- dithiolene gold (III) complexes, (3) cyclometalated and terpyridine gold (III) complexes.Firstly, three Platinum complexes, M1(R¹,R²=H), M₂(R¹,R²=CH₃) and M3(R¹=Cl,R²=H) were geometrically optimized for the cationic, anionic in the condition of neutral states. And the optical properties were calculated based on the optimized geometries by employing TD-DFT. Furthermore, the energies of the highest-occupied molecular orbital (HOMO), the lowest-unoccupied molecular orbital (LUMO), and the variation of band gaps (E_g), ionization potentials (I_p), electron affinities (E_a), the maximum absorption, emission wavelengths, the electronic and optical properties of the complexes had been investigated. The calculated results showed that the absorption of M₃ exhibit gradual red-shifts.Secondly, six unsymmetrical organometallic-dithiolene gold (III) complexes, [Au(ppy) (C₈H₄S₈)](P₁), [Au(ppy) (C₈H₄S₆O₂)] (P₂), P₃, P₄, P₅ and P₆ were geometrically optimized for the cationic, anionic at neutral states. And the optical properties are calculated based on the optimized geometries by employing TD-DFT. Furthermore, the energies of the highest-occupied molecular orbital (HOMO), the lowest-unoccupied molecular orbital (LUMO), and the variation of band gaps (E_g), ionization potentials (I_p), electron affinities (E_a), the maximum absorption, the electronic and optical properties of the polymers had been investigated. The calculated results showed that the absorption of P₁ exhibit gradual red-shifts.At last, three gold complexes, L1,L2 and L3, were geometrically optimized for the cationic, anionic, and neutral states. Based on the optimized geometries, the optical properties are calculated by employing TD-DFT. Furthermore, Furthermore, the energies of the highest-occupied molecular orbital (HOMO), the lowest-unoccupied molecular orbital (LUMO), and the variation of band gaps (E_g), ionization potentials (I_p), electron affinities (E_a), the maximum absorption, the electronic and optical properties of the complexes had been also investigated. The calculated results indicated that the absorption of L1,L2,L3 exhibits gradual red-shifts.