Design Synthesis And Characterization Research Of Electron Transfer Photochromic Metal Coordination Compounds

Photochromic materials have a wide range of applications in photocatalysis,optical storage,adsorption,magnetism,light,nonlinear optics,decoration,anti-counterfeiting and camouflage,and other fields.Photochromic materials are divided into inorganic photochromic systems,organic photochromic systems,inorganic-organic photochromic system and biological photochromic system.Through the design synthesis with special functional groups of organic ligands and metal ions self-assembly,novel structure,excellent performance can be obtained in coordination polymer.The study of photochromic metal complexes has made great progress.Electron transfer photochromic metal complexes,due to their important applications in areas such as catalysis,optics,electricity,magnetic control,have attracted great attention.In the past decades,much effort has been paid in the traditional families of ET photochromic compounds such as viologens and polyoxometalates of VIB metals to perform their merits.In recent years,using the nonphotochromic ligands and metal ions in the composition of the new electronic transfer system of photochromic metal complexes,gained rapid development.The research idea of this paper:To design synthesis organic ligands with special functional groups,and react with metal ions to get metal complexes;Application of nonphotochromic ligands and metal ions reaction to get metal complexes.In this thesis,the metal complexes were synthesized,whose crystal structure and photochromic,photoluminescence and other aspects are studied and discussed.The major works of this thesis are outlined as following:1.Using 4,4'-bipyridine,crotonic acid and zinc ion under the different conditions of pH,through hydrothermal synthesis,we got two different structures of the complexes:[Zn2(Bpy)1.5(CTA)4·2H2O](1),[Zn2(Bpy)(CTA)4](2).And using 4,4'-bipyridine,2-methacrylic acid and zinc ion,we got the a compound through hydrothermal synthesis:[Zn2(Bpy)(maa)4](3).Compound 1 features a 1-D step-like chain structure with 4,4'-bipyridine coordinating the mono zinc ion or binuclear Zn connected alternatively.Compound 2 features an 1-D linear chain structure,where the binuclear Zn is bridged by the 4,4'-bipyridine.Compound 3 also features an 1-D linear chain structure,where the binuclear Zn is bridged by the 4,4'-bipyridine.We studied their photochromic,UV-Vis,fluorescence and ESR properties.We found that the compounds showed reversible electron transfer photochromism and the coloration rate of compound 2 significantly greater than 1,and both have adjustable fluorescent properties,fluorescence intensity is decreased obviously after the color change.2.Using the metal to modify the photochromic ligands,the compound[C36H32Br4N4O6Cd2](4)of a dual-core Cd cluster was obtained.Through the studies found that the compound has photochromic phenomenon.The modification of the photochromic behavior of metal to organic photochromic ligands is realized by the coordination of organic ligands and metal ions.3.Chiral organic small molecules[C14H20N2O5](5)and[C14H20N2O5](6)were synthesized and obtained the crystal structure of 5.We found that the compounds showed reversible electron transfer photochromism and photochromism caused the change of fluorescence,and the fluorescence intensity decreased significantly after the color change.