【作者】 王磊；

【导师】 刘春；

【作者基本信息】 大连理工大学 ， 应用化学， 2021， 博士

【摘要】 铱配合物因其具有较高的发光效率和较长的磷光寿命等优点受到广泛关注。但由于聚集导致猝灭（ACQ）效应的影响,使其在固态下的应用受到了极大地限制。因此,开发具有聚集诱导发光（AIE）性质的铱配合物成为当前的研究热点。作为一类有潜力的氧敏感探针（OSPs）,如何从分子水平理解铱配合物的结构与氧传感性能的关系,是一个有重要意义的研究课题。本论文设计合成了系列含二苯氨基的环金属铱配合物,探究了铱配合物的结构与其光物理、电化学性质的关系,并重点研究了配合物的聚集诱导磷光发射（AIPE）性质和氧传感性能。主要研究内容包括以下四部分:（1）以1,10-邻菲罗啉为辅助配体,向环金属配体引入苯基、二苯氨基及咔唑基等可旋转基团,合成了配合物Ir1-Ir4。系统研究了环金属配体的结构对配合物的光物理、电化学性质和氧传感性能的影响。结果表明,向环金属配体引入苯基或咔唑基导致相应配合物的发射光谱蓝移,能级差增大,磷光寿命延长;而引入二苯氨基的Ir4,其最大发射波长明显红移,能级差减小,磷光寿命缩短且量子产率降低。此外,配合物Ir4在乙腈/水体系中表出明显的AIPE性质,且在乙基纤维素（EC）膜上表现出较高的氧敏感性。（2）设计合成了在环金属配体的吡啶环的5位分别引入CF₃、CN、F和CH₃的配合物Ir5-Ir8,系统研究了取代基对配合物发光性质和氧传感性能的影响。结果表明,引入吸电子基CF₃和CN的配合物Ir5和Ir6的最大发射波长蓝移,能级差增大,量子产率显著增加,磷光寿命延长,其在CH₂Cl₂溶液中和EC膜上均具有较高的氧敏感性。配合物Ir5-Ir8在乙腈/水体系中均展现出AIPE性质,透射电镜研究表明Ir5、Ir7和Ir8三个配合物在乙腈/水体系中均形成球形聚集体。（3）设计合成了在环金属配体的吡啶环的5位和6位分别引入F或CH₃的配合物Ir7-Ir10,研究了取代基的不同位置对配合物发光性质和氧传感性能的影响。结果表明,取代基在6位的配合物Ir9和Ir10,其发光蓝移、能级差增大、量子产率增加且磷光寿命延长。配合物Ir7、Ir8和Ir10在乙腈/水体系中均具有AIPE性质,而在吡啶环的6位引入F的Ir9却表现出ACQ现象,在CH₂Cl₂溶中和EC膜上均具有最高的氧敏感性。（4）设计合成了三苯胺修饰的铱配合物Ir11和Ir12,研究了三苯胺基团对配合物发光性质和氧传感性能的影响。结果表明,环金属配体引入三苯胺的配合物Ir11和Ir12,其最大发射波长发生明显蓝移、磷光寿命延长并且在EC膜上的氧敏感性明显增强。此外,配合物Ir11和Ir12在乙腈/水体系中都表现出AIPE性质,透射电镜研究表明两个配合物在乙腈/水体系中均形成球形聚集体。更多还原

【Abstract】 Iridium complexes have attracted much attention due to their high luminous efficiency and long phosphorescence lifetime.However,due to the effect of aggregation-induced quenching（ACQ）,the application of iridium complexes in the aggregated state and the solid state has been greatly limited.Thus,the design and development of iridium complexes with aggregation-induced luminescence（AIE）properties have become a research hotspot at the present.In addition,as potential oxygen-sensitive probes（OSPs）,understanding the effects of the structures of iridium complexes on their oxygen sensing properties at the molecular level is of great importance.In this paper,a series of diphenylamino-substituted cyclometalated iridium complexes were designed and synthesized.The relationship between the structures of iridium complexes and the photophysical and electrochemical properties was investigated,the aggregation-induced phosphorescent emission（AIPE）and oxygen sensing properties has been investigated systematically.The main research contents include the following four parts:（1）The iridium complexes Irl-Ir4 modified with a rotatable unit of benzene ring,diphenylamino（DPA）or carbazole group at the cyclometalating ligands were synthesized.The effects of the cyclometalated ligands on the photophysical,electrochemical properties and oxygen sensing performances of the complexes were studied in detail.The results show that the introduction of a phenyl or a carbazole moiety into the cyclometalating ligand leads to a blue shift of the emission,an increased Eg energy level and a prolonged phosphorescence lifetime;while the DPA-substituted Ir4 has a red shifted maximum emission,a decreased Eg energy level and a shorter phosphorescence lifetime.In addition,the complex Ir4 shows obvious AIPE properties in an acetonitrile/water system and high oxygen sensitivity immobilized on an ethyl cellulose（EC）film.（2）The iridium complexes Ir5-Ir8 with different substituents at the 5-position of the pyridine ring on the cyclometalated ligands were designed and synthesized.The effect of substituents on the luminescence properties and oxygen sensing properties of the complexes were systematically studied.The results show that the introduction of an electron-withdrawing group CF₃（Ir5）or CN（Ir6）leads to a blue-shifted emission,a prolonged phosphorescence lifetime and increased Eg energy levels.Both complexes demonstrate high oxygen sensitivity in CH₂Cl₂ and EC film.The iridium complexes substituted with CF₃（Ir5）,CN（Ir6）,F（Ir7）or CH₃（Ir8）,exhibit AIPE properties in the acetonitrile/water system.Transmission electron microscopy（TEM）studies show that complexes Ir5,Ir7 and Ir8 formed spherical aggregates in the acetonitrile/water system.（3）The iridium complexes Ir7-Ir10 with a F or CH₃ group at the 5-or 6-position of the pyridine ring at the cyclometalating ligands were synthesized.The effects of the substituent position on the luminescence properties and oxygen sensing performances of the corresponding complexes were systematically studied.The results show that the complexes Ir9（6-F）and Ir10（6-CH₃）with the substituent at the 6-position have a blue-shifted emission,an increased Eg energy level,a higher quantum yield and a longer phosphorescence lifetime.The iridium complexes Ir7（5-F）,Ir8（5-CH₃）and Ir10 are AIPE-active in the acetonitrile/water system.However,the 6-F modified Ir9 exhibits an ACQ phenomenon,and has the highest oxygen sensitivity in CH₂Cl₂ and EC film.（4）The iridium complexes Ir11 and Ir12 modified by triphenylamine group at the cyclometalating ligands were synthesized,and the influence of triphenylamine group on the luminescence properties and oxygen sensing performance of the complexes were studied.The results show that the triphenylamine-modified complexes Ir11 and Ir12 have a significant blue-shifted emission,a prolonged phosphorescence lifetime and enhanced oxygen sensitivity on the EC films.In addition,the complexes Ir11 and Ir12 exhibit AIPE properties and form spherical aggregates in the acetonitrile/water system.更多还原