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Affiliation of Author(s):化学与生命科学学院
Teaching and Research Group:化学教研室
Journal:Journal of Luminescence
Funded by:国家自然科学基金项目
Abstract:We report a quantum-chemical study on the electronic structures and optical properties of two series of heteroleptic iridium(III) complexes [(dfb-pz)2Ir(N∧ N+sub)], [dfb-pz¼2,4-difluorobenzyl-N-pyrazole, sub indicates substituent group, N∧ N+sub¼tphppz¼4-tert-butyl-2-(5-phenyl-[1,2,4]triazol-3-yl)-pyridine (1a), tmppz¼4-tert-butyl-2-(5-methyl-[1,2,4]triazol-3-yl)-pyridine (1b), fphppz¼4-fluoro-phenyl-5-(2- pyridyl)pyrazole (1c), and fmphppz¼4-trifluoromehtyl-phenyl-5-(2-pyridyl)pyrazole (1d)]; with [(C∧ N +sub)2Ir(fppz)], [C∧ N¼b-pz¼benzyl-N-pyrazole, fppz¼3-trifluoromethyl-5-(2-pyridyl)pyrazole, C∧ N +sub¼dfb-pz¼2,4-difluorobenzyl-N-pyrazole (2a), tfmfb-pz¼2-trifluoromethyl-5-fluorobenzyl-N-pyr- azole (2b), phb-pz¼3-phenyl-benzyl-N-pyrazole (2c), and dfphb-pz¼3-phenyl-2,4-difluorobenzyl-N- pyrazole (2d)]. The calculated results shed light on the reasons of the remarkably manipulated excited- state and electroluminescent properties through substitution effect. The phenyl ring on main ligands can enhance the π-conjugation of the main ligands moiety and increase the metal-ligand bond strength for 2c and 2d, then enhancing the transition strength. From 1c, 1d, 2c, and 2d, it can also be seen that substituents on the terminal phenyl ring have a slight effect on the excited energy because the distance between the substituents and the ancillary (or main) ligand is interrupted by the phenyl moiety. The calculated absorption and luminescence properties of the four complexes 1a, 1b, 2a, and 2b are compared with the available experimental data and a good agreement is obtained. Furthermore, the assumed complex 1c, 2c, and 2d possess better charge transfer abilities and more balanced charge transfer rates. The designed complexes 2c and 2d are potential candidates for blue phosphorescent materials.
Co-author:刘雨琦,曲晓春,武志坚
First Author:shangxiaohong
Indexed by:Journal paper
Volume:143
Page Number:1
Translation or Not:no
Date of Publication:2013-11-01