Structural Regulation And Optical Properties Of [CuI(N^N)P] Type Coordination Compounds

Luminescent metal-organic materials show amazing application prospects on organic light-emitting diodes,chemical sensors,light-emitting electrochemical cells,and so on.Environmentally friendly,cheap and low toxic copper?I?luminescent complexes have attracted more and more attention due to their varied structural types and excellent optical properties.Herein,we have designed and synthesized a series of[CuI?N^N?P]type luminescent coordination compounds,which are co-constructed by nitrogen-donating and phosphine ligands.The crystal structures of the complexes have been confirmed by X-ray single crystal diffraction and characterized by X-ray powder diffraction,infrared spectra,elemental analyses and UV-Vis absorption spectra.The optical properties and thermal stabilities of the complexes have been further studied.The structural influencing factors of[CuI?N^N?P]type luminescent coordination compounds have been analysed.Combined with TD-DFT calculation,the relationship between the structures and optical properties of the complexes has also been discussed.The main content of the thesis is listed as following:1.Structural regulation and optical properties of[CuI?N^N?P]type coordination compounds based on PBI ligands.We have designed and synthesized three nitrogen-donating ligands:2-?2-pyridyl?benzimidazole?2-PBI?,3-methyl-2-?2-pyridyl?benzimidazole[2-PBI?3-CH₃?]and 2-?2-pyridyl?benzothiazole?2-PBS?.Ten novel[CuI?N^N?P]type coordination compounds have been synthesized by the co-construction of nitrogen-containing ligands,phosphine ligands and cuprous iodide,namely:[Cu I?2-PBI??TPP?]?1?,{[CuI?2-PBI??TPP?]·CH₃CH₂OH}?2?,{[CuI?2-PBI??TPP?]·CH₂Cl₂}?3?,{Cu I?2-PBI?[TPP?3-CH₃?]}?4,5?,{CuI?2-PBI?[TPP?3-CH₃?]}{Cu I?2-PBI?[TPP?3-CH₃?]}·C₃H₆O?6?,{CuI?2-PBI?[TPP?3-OCH₃?]}?7?,[CuI?2-PBI??TXP-2,4?]?8?,{Cu I[2-PBI?3-CH₃?][TPP?3-CH₃?]}?9?,{[CuI?2-PBS??TPP?]·CH₂Cl₂}?10?.The single crystal structural analyses show that the stuctures of complexes are all of[CuI?N^N?P]type.Complexes 4 and 5 are a pair of isomers.There are solvent-induced isomerization phenomena in the structures of complexes 1-3 and 4-6,respectively.The structural influencing factors of the complexes have been analyzed.The steric hindrance of the phosphine ligands has been revealed to affect the twist degree of coordination configuration at the coordination center.The solvent-induced isomerization is found due to the presence of hydrogen bonds.These complexes at solid state show excellent luminescent properties at room temperature.The solvent-induced luminescent discoloration phenomena have been initially explored.The relationship between the structures and optical properties of the complexes has also been studied.The incorporation of electron-donating groups into the phosphine ligand will lead to the red-shift of the emission wavelength.The stronger the electron-donating property in the phosphine ligand exhibits,the greater red-shift of the emission wavelength appears.2.Structural regulation and optical properties of[CuI?N^N?P]type coordination compounds based on the phosphine ligand with bulky steric hindrance.Four novel copper?I?complexes:{Cu I?2-PBI?[2-?Dpp?bp]}?11?,{CuI?Phen?[2-?Dpp?bp]}?12?,{Cu₂??-I?₂?Phen?[2-?Dpp?bp]}?13?,{CuI?Bipy?[2-?Dpp?bp]}?14?have been synthesized by 2-?diphenylphosphino?-biphenyl[2-?Dpp?bp],different nitrogen-donating ligands and cuprous iodide.The single crystal structural analyses show that the structures of complexes are all of[Cu I?N^N?P]type,except for complex 13,which is a binuclear complex and has formed a pair of isomerism polycrystalline complexes with complex 12.The structural influencing factors of the complexes have been analyzed.When a nitrogen-containing ligand with small steric hindrance has been applied,the phosphine ligand plays a dominant role in affecting the twist degree of coordination configuration at the coordination center.Complex 11-13 at solid state show excellent luminescent properties at room temperature.Combined with TD-DFT calculation,the relationship between the structures and optical properties of the complexes has also been studied.The nitrogen-containing ligands have occupied the level of LUMO orbitals,further affecting the luminescent wavelength.The emission of the complexes mainly derived from metal-ligand charge transfer?MLCT?as well as halide-ligand charge transfer?XLCT?.