Synthesis,Crystal Structure And Third-order Nonlinear Optical Properties Of Cyclometalated Iridium Complexes

Metal-organic complexes were widely used in catalysts,analytical tests,function al materials,biomedicine,etc.due to the combination of both inorganic and organic pr operites.Among the metal-organic complexes,cyclometalated iridium complexes have attracted much attention due to their excellent light-emitting properties,and have been used in many fields such as OLEDs,LECs,cell imaging,and chemical sensing.In recent years,cyclometalated iridium complexes with good second-and third-order nonlinear optical responses have been reported,and their nonlinear optical properties can be adjusted in various ways?such as introducing electron donating/withdrawing groups,increasing the conjugation of the system effects,etc.?.In addition,the charge transfer between the metals and the ligands as well as the charge transfer between the ligands can also effectively adjust the nonlinear optical response of the cyclometalated iridium complexes.The dissertation focuses on the synthesis and characterization of metal-organic complexes.Eight new cyclometalated iridium complexes based on precursor building blocks[?ppz?₂Ir??-Cl?]₂ or[?ppz?₂Ir??-Cl?]₂ have been prepared.The structure-property relationship of these complexes has been investigated by studying the effects of structure changes for cyclometalated iridium complexes on third-order nonlinear optical properties,photophysical properties,and thermal stability.It lays a foundation for the further use of molecular engineering technology to control the nonlinear optical properties in order to develop new nonlinear optical materials.1.Six cyclometalated iridium complexes were obtained by the reaction between iridium dichloride bridge compound[?ppz?₂Ir??-Cl?]₂ and benzimidazole ligands?BzImHImH,BiBzImH₂,BiBzImDNH?,as well as benzophenanthroline ligands?DiHDiPPhen,DiBrDiHDiPPhen,DiPDiHDiPPhen?.The effects of introducing electron donor/withdrawing groups to auxiliary ligands on the photophysical properties,third-order nonlinear optical properties,thermal stability and crystal structure of cyclometalated iridium complexes are discussed.2.The structure of cyclometalated iridium complexes were regulated by modifying the chelating ligands.A strong electron withdrawing group was introduced into the benzene ring of chelating ligand 1-phenylpyrazole,which reacts with IrCl₃·3H₂O to synthesize[?dfppz?₂Ir??-Cl?]₂.Two cyclometalated iridium complexes were obtained by the reaction between N^N ligand 1,4-bis?2,2'-bipyridine?benzene and two iridium dichloride bridged precursors[?dfppz?₂Ir??-Cl?]₂ and[?ppz?₂Ir??-Cl?]₂,while the influence of structural changes for chelating ligand on photophysical properties and third-order nonlinear optical properties of cyclometalated iridium complexes have been investigated.1.[Ir?ppz?₂?BzImHImH?][PF₆]2.[Ir?ppz?₂?BiBzImH₂?][PF₆]3.[Ir?ppz?₂]₂?BiBzImDNH?4.[Ir?ppz?₂?DiHDiPPhen?][PF₆]5.[Ir?ppz?₂?DiBrDiHDiPPhen?][PF₆]6.[Ir?ppz?₂?DiPDiHDiPPhen?][PF₆]7.[Ir?ppz?₂?DiBipyP?][PF₆]8.[Ir?dfppz?₂?DiBipyP?][PF₆]...