三-(2-苯基吡啶)-铱及其衍生物电子结构、电子光谱及取代基效应的密度泛函理论研究

Theoretical Studies of Electronic Structures, Electronic Spectra and Substituent Effect in Cyclometalated Phenylpyridine Ir(Ⅲ) Complex and Its Derivatives Using Density Functional Theory

采用密度泛函理论 ( DFT) B3 LYP/Lan L2 dz方法 ,对一类重要的磷光材料三 -( 2 -苯基吡啶 ) -铱[Ir( ppy) 3]及其衍生物的电子结构与电子光谱进行了研究 ,讨论了取代基对配合物的能级和 LUMO-HOMO能隙的影响 ,发现吸电子基 (— CN)使能级降低 ,HOMO-LUMO之间能隙减小 ,而推电子基 (—OCH3)使能级升高 。

The ground state and electronic spectra in the Ir(Ⅲ) complex Ir(ppy) 3[where ppy=2-phenylpyridine], an important phosphorescent material, and its derivatives were studied by using density functional theory(DFT) B3LYP/LanL2dz in programme Gaussian 98. The effects of substituted groups on energies and gaps of HOMO-LUMO were discussed. It is found that electron-withdrawing substituent(—CN) makes both orbital energies and gaps of HOMO-LUMO decrease, whereas electron-releasing substituent(—OCH 3) makes orbital energies increase and gaps of HOMO-LUMO relatively unvaried.