Syntheses,Crystal Structure And Nonlinear Optical Properties Of Iridium Metal Organic Complexes

Metal-organic complexes have attracted much attention due to their structural diversity and application in many fields such as optical materials,drugs,catalysis,cell imaging and biometrics.In recent years,the design and synthesis of metal-organic complexes with specific structures and properties has become a research focus in the field of chemistry and material.Among the numerous synthetic methods for metal organic complexes,the precursor construction method is gaining more and more attention because of its special stability.The metal iridium dimer with good photothermal stability was introduced as a precursor to construct metal organic complexes with different types of organic ligands towards the structures and properties.Specific structures of eight metal organic complexes based on nitrogen-containing organic ligands were synthesized by solvent diffusion method at normal temperature.At the same time,the third-order nonlinear optical properties of these metal organic complexes were studied by Z-scanning method.In addition,two metal organic complexes 7 and 8 monomer were selected for chemical covalent modification of graphite oxide nanomaterials by esterification reaction to obtain the composite materials with superior nonlinear optical properties.1.Six iridium metal complexes with novel structures were obtained by the reaction between iridium dimer precursor[Ir（dfppy）₂（μ-Cl）]₂ reacted and three schiff base nitrogen-containing ligands（bzp,pmana,pma-NO₂）,as well as three azines ligands（pytz-PhMe,pytz-SiMe₃,pytz-PhNO₂）.All these Metal-organic complexes have been characterized by single-crystal X-ray diffraction.It is revealed that three metal schiff base complexes belonged to monoclinic system,while three pyridazine crystals belonged to monoclinic,triclinic and monoclinic system,respectively.The properties of six iridium metal-organic complexes were characterized by UV-Vis absorption spectroscopy,fluorescence emission spectroscopy,thermal analysis and Z-scanning.It was found that enhancing the ligand conjugated structure or introducing electron withdrawing group can improve the nonlinear optical properties of complex.[Ir（dfppy）₂（bzp）]·PF₆·CH₂Cl₂（1）[Ir（dfppy）₂（pmana）]·PF₆（2）[Ir（dfppy）₂（pma-NO₂）]·PF₆·CHCl₃（3）[Ir（dfppy）₂（pytz-PhMe）]·PF₆·CH₂Cl₂（4）[Ir（dfppy）₂（pytz-SiMe₃）]·PF₆·CH₂Cl₂·CH₃OH（5）[Ir（dfppy）₂（pytz-PhNO₂）]·PF₆（6）2.Two kinds of iridium metal complexes 7 and 8 were obtained by iridium dimers coordinated with two different chelating organic nitrogen-containing auxiliary ligands with amino groups.After that,7 and 8 were covalently connected to the surface of graphene oxide to obtained two metal organic small molecule functionalized graphene oxide materials.In addition,the performance characterized by UV-visible absorption,fluorescence emission spectrum,thermal stability and nonlinear absorption indicating that the successful preparation of two composite materials.The Z-scan test found that the composite material has better third-order nonlinear optical absorption properties than the iridium metal organic complex and GO.[Ir（ppy）₂（bpt-NH₂）]·PF₆·2C₃H₆O（7）[Ir（dfppy）₂（pma-NH₂）]·PF₆·CH₂Cl₂（8）...