The Properties Of Solvatochromic And Construction Of Spin Crossover Behavior Metal Complex By Pyridine Bisoxazoline Ligand

In recent years,the field of magnetism has been continuously fused with life sciences,chemistry,physics and other disciplines to construct multifunctional materials.The combination of magnetism and fluorescence has been one of the research hotspots in recent years.Therefore this thesis attempts to introduce fluorophore into metal complexes to explore dual functional materials with magnetism and fluorescence.The specific research content is as follows:1.Organic ligands with fluorophore were synthesized and characterized.In this part,Isynthesized a series of triphenylpyrrole modified pyridine bisoxazoline（Py Box）ligands L¹,L²,and L³.The optical properties of ligands L¹ and L² were explored by ultraviolet visible absorption spectroscopy and fluorescence spectroscopy.The results showed that both ligands L¹ and L² have obvious intramolecular charge transfer characteristics,and ligand L¹ has obvious solvatochromic properties.The fluorescence intensity of ligand L¹was closely related to the polarity of the solvent and strong polar solvents will significantly reduce its fluorescence intensity.Fluorescence of ligand L¹ was almost quenched in the Protic solvents（methanol and water）.2.Magnetism and optical properties of metal complexes（Fe and Zn）.In this part,I used ligand L¹ to construct complexes[Zn（L¹）₂]（Cl O₄）₂ and[Fe（L¹）₂]（Cl O₄）₂.The structures of the two complexes were characterized by single crystal X-ray diffraction.Approximately 28.2%of the Fe（II）ions in the complex[Fe（L¹）2]（Cl O4）2 have undergone spin transition process in the test temperature range of 2-400K.Complex display incomplete spin crossover behavior in the test temperature range.Test results of ultraviolet visible absorption spectroscopy and fluorescence spectroscopy showed that complex[Zn（L¹）2]（Cl O4）2 has a significant solvatochromic phenomenon and wide solvent selectivity.The fluorescence intensity of complex[Zn（L¹）2]（Cl O4）2 was closely related to the polarity of the solvent and the presence of an appropriate ratio of poor solvent will significantly enhance the luminescence of the complex[Zn（L¹）2]（Cl O4）2.The difference between the fluorescence quenching of ligand L¹ in methanol solution was that the fluorescence of the complex[Zn（L¹）₂]（Cl O₄）₂ in methanol solution was significantly enhanced.