Nitrogen-containing Heterocyclic Ligands And Their Complexes, Synthesis And Structural Characterization

The geometric configuration of ligand and the coordination tendency of metal cation should be considered when constructing the coordination polymers. In this paper, we designed and synthesized three N-heterocyclic ligands, they are 1,4-bis (pyrazole-1-ylmethyl)benzene(L1),4,4'-bis(pyrazole-1-y1methyl)biphenyl(L2),4,4'-bis(imidazole-1-ylmethyl)biphenyl(L3), and we have synthesized ten transitional metal complexes. All complexes have been characterized by Elemental analyses, Infrared(IR), Ultraviolet-Visible(UV), Thermal gravimetric analysis. Ten new complexes have been characterized by single-crystal X-ray crystallographic analysis. In addition, we investigated their fluorescent properties, most of which exhibit good fluorescent properties and have potential uses in fluorescent material.The pyrazole has connected with the benzene in the ligand is prone to distort and to get a much higher dimension in the complex. Namely, compound 1 is a three dimensional network, and compound 2 is a two dimensional grid, then compound 3 is a one dimensional chain and the last one, compound 4 is a two dimensional ladder shape configuration. Relatively, if we change benzene to biphenyl, which is in the result of the ligand is not easy to distort, although anti-balanced anions is different, the anti-balanced anions are all connected to the center metal atom, so they are prone to be one dimensional chain (6,7,8 and 9). Nevertheless, we can see that the configuration is also can be influenced by changing the metal atoms, for instance, compound 5 is a three dimensional mutual interaction figure. Compound 10 is synthesized by ligand L3 with copper acetate to form a one dimensional chain without the H2O coordinating the metal atom.