[Ir(ppy)2(py-x)]+配合物的密度泛函理论研究

从理论上研究了一系列[Ir(ppy)2(py-H)]+ (1)，[Ir(ppy)2(py-pr]+ (2)，[Ir(ppy)2(py-pz)]+(3) [ppy=苯基吡啶，py=双（吡唑-1-基）甲烷，pr=吡咯，pz=吡唑]配合物的几何构型和光谱特征。采用密度泛函和单激发组态相互作用方法优化了基态和激发态结构，用含时密度泛函结合溶剂化模型计算三个分子在CH2Cl2溶剂中的光谱特征。基态优化得到Ir-N1、Ir-N4和Ir-N6与相应的实验值符合良好，激发态几何构型相对于基态变化较小，这与斯托克斯频移现象相符。配合物1-3的最低能吸收分别在399.07 nm、401.68 nm和396.15 nm，其磷光发射分别在513.00 nm、513.78 nm和510.38 nm，其最高占据轨道(HOMO)主要由金属Ir和配体ppy占据，而分子1和2最低空轨道(LUMO)均为ppy配体占据的π*型轨道，其跃迁属性为金属到配体和配体内部的电荷转移(MLCT/ILCT)跃迁，分子3的LUMO是由ppy和py配体占据的π*型轨道，其跃迁属性仅为金属到配体(py)的跃迁(MLCT)。研究结果表明，在非共轭配体py上引入取代基团不会对配合物发光颜色产生重要影响。

Density Functional Theory Study on A Series of [Ir(ppy)2(py-x)]+ Complexes

The spectral characteristics of [Ir(ppy)2(py-H)]+(1), [Ir(ppy)2(py-pr)]+(2), [Ir(ppy)2 (py-pz)]+(3) [ppy = phenylpyridine, py = bis(pyrazol-1-yl)methane, pr = pyrrole, pz = pyrazole] complexes were studied theoretically. The density functional and the single excitation configuration interaction method are used to optimize the ground state and excited state structure, and the time-dependent density functional theory combined with the polarized continuum model is used to calculate the absorption and emission spectra of complexes 1-3 in the CH2Cl2 solution. The bond lengths of Ir-N1, Ir-N4 and Ir-N6 in the ground state are in good agreement with the corresponding experimental values, and the geometric configuration of the excited state changes little relative to the ground state, which is consistent with the stokes frequency shift phenomenon. The lowest energy absorption of complexes 1-3 at 399.07 nm, 401.68 nm and 396.15 nm, and the phosphorescence emission at 513.00 nm, 513.78 nm and 510.38 nm, respectively. The highest occupied molecular orbital (HOMO) of these complexes is mainly occupied by Ir and ppy ligand, while the lowest unoccupied molecular orbital (LUMO) of 1 and 2 is occupied by the π*-type orbital of the ppy ligand, this transition is referred to as the metal to ligand and intraligand charge transfer transition(MLCT/ILCT). However, the LUMO of molecule 3 is occupied by the π* orbitals of the ppy and py ligands, its transition property is only the transition from metal to py-pz ligand (MLCT). The research results show that the introduction of substituent groups on the non-conjugated ligand py will not have an important effect on the color of these complexes.