Synthesis, Characterization, And Properties Of Functional Complexes Based On The Backbone Of 8-Hydroxyquinoline

Herein, a variety of functional ligands based on 2-substituted 8-hydroxyquinoline skeletons with different structures and functions were synthesized. Based on coordination and supramolecular chemistry, a series of crystalline materials with unique structures and properties were prepared. The as-synthesized compounds were characterized by X-ray single crystal diffraction, IR spectrum, NMR spectroscopy and elemental analysis. This thesis includes the following four chapters.In Chapter 1, We summarized the recent development of 8-hydroxyquinoline materials, their potential applications in optics, the challenges remained in this area. Additionally, an overview of the thesis topic and progress were also presented.In Chapter 2, three 8-hydroxyquinoline ligands HL1、HL2 and HL3 was prepared in two steps. This Chapter includes the following three parts. First of all, anion-controlled structures and luminescent properties of three Cd(II) complexes assembled by a 2-substituted 8-hydroxyquinoline ligand were studied, As a result, the three Cd(II) complexes exhibit disparate photophysical properties. Secondly, this work reports the synthesis, crystal structures and properties of one binuclear zinc complex from(E)-2-[2-(4-methoxyphenyl)ethenyl]-8-hydroxyquinoline ligand, The results showed that binuclear zinc complex exhibits a red shift compared with free ligand and emits yellow luminescence. Finally, two two-folded helical structures based on 2-substituted 8-hydroxyquinoline complexes were prepared and characterized. The results of investigation show that above helical structure can be tuned by the supramolecular interactions, The present research holds great promise in the development of novel functional helical structure, and may contribute to the understanding of helical organized systems in biology.In Chapter 3, two 8-hydroxyquinoline ligands modified by two pyridyl groups(HL4 and HL5) were synthesized in three steps. Based on different anions and ligands, three coordination polymers were fabricated by the self-assembly of the Zn(II) ions with the ligands using the solvothermal method. In addition, we also studied the luminescent properties of these compounds in the solid state. The results showed that these complexes exhibit same emission wavelength and different fluorescence lifetime. Interestingly, the three coordination polymers is capable of selective recognizing nitroaromatic molecules via fluorescence quenching in the solid state.In Chapter 4,(E)-2-[2-(3-pyridyl)ethenyl]-8-hydroxyquinoline ligand HL6 were synthesized in two steps. And six coordination polymers with different structures(1D chains and 2D networks) were constructed by the self-assembly of the Zn(II) and Cd(II) ions with the ligand. In addition, we also studied the luminescent properties of these compounds in the solid state. The results show that coordination polymers exhibit a red shift compared with free ligand HL6, and emit green luminescence. Interestingly, different fluorescence lifetime of six polymers were observed.