环金属配体Ir(Ⅲ)配合物结构、光谱和量子效率的理论研究  

Theoretical Study of Structure,Spectra and Quantum Efficiency for a Series of Iridium(III)Complexes with the Cyclometalating Ligand

作　　者：聂建航 王天奇 金丽[1] 张建坡[1] 张红星[2] 白福全 NIE Jianhang;WANG Tianqi;JIN Li;ZHANG Jianpo;ZHANG Hongxing;BAI Fuquan(School of Chemical and Pharmaceutical Engineering,Jilin Institute of Chemical Technology,Jilin 132022,China;Institute of Theoretical Chemistry,International Joint Research Laboratory of Nano-micro Architecture Chemistry,College of Chemistry,Jilin University,Changchun 130023,China)

机构地区：[1]吉林化工学院化学与制药工程学院,吉林132022 [2]吉林大学化学学院,理论化学研究所,纳米微结构化学国际联合研究实验室,长春130023

出　　处：《高等学校化学学报》2024年第4期78-86,共9页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:21873038,21573088)资助。

摘　　要：对一类环金属Ir(Ⅲ)[(C^N)_(2)Ir(A^A)]配合物[C^N=ptaz(1,2,4),mhtz(3),ptaz=3,4,5-三苯基-4H-1,2,4-三唑,mhtz=1,3-双甲基-5-苯基-1H-1,2,4-三唑;A^A=pzpy(1),npzpy(2,3),bicb(4),pzpy=2-(1H-吡唑-1-基)吡啶,npzpy=4-二甲基氨基-2-(1H-吡唑-1-基)吡啶,bicb=3,3′-亚甲基双(1-甲基-1H-咪唑-2-亚基)]的结构、光谱特征和磷光量子效率进行了理论研究.计算方法探究表明,基于B3LYP泛函优化的基态结构和单激发组态相互作用(CIS)方法得到的激发态结构计算的吸收和发射光谱更准确.配合物1~4的最低吸收峰和发射峰分别位于408,376,382,365 nm和503,506,468,511 nm处,其HOMOs主要由金属和C^N配体占据,而配合物1~3的LUMOs由A^A配体的π反键轨道组成,配合物4的LUMO存在于C^N配体上.因此,配合物4的最低吸收峰和发射峰具有与配合物1~3不同的金属到配体和配体内部(MLCT/ILCT)的混合跃迁性质,非共轭N^N配体的引入显著消弱了其在跃迁过程中的贡献程度.配合物1~4的量子效率取决于非辐射跃迁速率常数k_(nr),这与它们重组能的贡献[4569 cm^(-1)(3)>2583 cm^(-1)(1)>1232 cm^(-1)(2)>975 cm^(-1)(4)]相一致,表明主配体的体积和辅助配体的共轭能力都能影响配合物的磷光量子效率.A series of cyclometalated iridium(III)complexes[(C^N)_(2)Ir(A^A)][C^N=ptaz(1,2,4),mhtz(3),ptaz=3,4,5-triphenyl-4H-1,2,4-triazole,mhtz=1,3-dimethyl-5-phenyl-1H-1,2,4-triazole;A^A=pzpy(1),npzpy(2,3),bicb(4),pzpy=2-(1H-pyrazol-1-yl)pyridine,npzpy=4-dimethylamino-2-(1H-pyrazol-1-yl)pyridine,bicb=3,3′-methylenebis(1-methyl-1H-imidazole-3-ium2-ide)]was investigated theoretically to explore their structures,spectroscopic properties and quantum efficiencies.The exploration of calculation methods shows that,the ground state structure optimized based on B3LYP functional and the excited state structure obtained by configuration interac⁃tion singles(CIS)method yield more accurate absorption and emission spectra.The lowest energy absorption and emission of complexes 1-4 at 408,376,382,365 nm and 503,506,468,511 nm,respectively.The HOMOs of complexes 1-4 are dominantly localized on the d(Ir)andπ(C^N)ligand,while the LUMOs of complexes 1-3 are composed ofπ*(A^A)ligands,however,the LUMO of complex 4 resides on theπ*(C^N)ligand.Therefore,the lowest energy absorption and emission of complex 4 exhibit mixed transition properties from metal to ligand and intra-ligand(MLCT/ILCT)that differ from complexes 1-3,the introduction of non-conjugated N^N ligands significantly weakens their contribution in the transition process.The quantum efficiency of complexes 1-4 depends on the magni⁃tude of the non-radiative rate constant k_(nr),this is consistent with their contribution to reorganization energy of 4569 cm^(-1)(3)>2583 cm^(-1)(1)>1232 cm^(-1)(2)>975 cm^(-1)(4),this indicates that the size of the main-ligand and the conjuga⁃tion ability of the auxiliary ligand can both affect the phosphorescence quantum efficiency of these complexes.

关 键 词：环金属铱(Ⅲ)配合物 电子结构 光谱特征 量子效率 

分 类 号：O641[理学—物理化学]