Synthesis, Structures, And Properties Of Complexes Based On Transition Metal/Rare Earth Metal-amino Acid/Zwitterionic Dicarboxylate

Until now, a fairly large number of research in our country and abroad covers on the formation and applying study of the metal-organic complexes, which is owing to their intriguing structures,diverse properties, and potential applications, such as gas storage and separation, fluorescence,magnetism, catalysis, and so on. Through tireless efforts, two organic complexes containing N and O atoms are chose as ligands. They are flexible with five- or six-number circle. One of two is an amino acid, called L-Thioproline(LTP). And the other one is a zwitterionic dicarboxylate ligand1,1’-(1,4-phenylene-bis(methylene))-bis(pyridine-3-carboxylic acid)(L).In this report, 10 metal-organic complexes have been prepared based on LTP and L via the solvothermal reaction, which coordinated with the rare-earth metals and transition metals,respectively. The IR spectra, elemental analyses, thermal analyses, XRD and single-crystal X-ray diffraction of 1?10 have been measured. Furthermore, luminescent properties of the title compounds and electrochemical behavior of 8?CPE have been investigated at room temperature. The major structures of title compounds and characters are as following.1. Six high-heteronuclear clusters, consisting of transition metals and rare-earth metals based on LTP, have been prepared, with the formula [La Ni6(LTP)12]?3(NO3)(1),[Ce Ni6(LTP)12]?3(NO3)(2), [Pr Ni6(LTP)12]?3(NO3)(3), [Nd Ni6(LTP)12]?3(NO3)(4),[Sm Ni6(LTP)12]?3(NO3)(5) and [Gd Ni6(LTP)12]?3(NO3)(6). Compounds 1?6 can be described as hepta-nuclear hetero-clusters. X-ray single-crystal structural analyses indicate that 1?6 are isomorphic with the triclinic P?1 space group. A twelve-coordinated Ln3+ ion is located in the center of a distorted octahedron. Each vertex of the octahedron is situated by a six-coordinated Ni2+ ion. LTP plays an important role in linking the Ln3+ ion and the Ni2+ ion. Furthermore,luminescent properties of the title complexes have been investigated at room temperature.2. Four new complexes have been prepared based on the transition metals and L, whoseformulas are [Zn(L)Cl2]n(7),[ Co(L)Cl2]n(8), [Cd(L)Cl2]n(9) and {[Cd4(L)(SO4)]·(Cl)6}n(10)respectively. X-ray single-crystal structural analyses show that compounds 7?9 crystallize in orthorhombic space group Cmca, exhibiting a 1?D zigzag chain, which can be linked to generate a 2?D layer via hydrogen bonding interactions(C?H···O). they are with excellent thermostability,degraded until 234 ℃. Moreover, electrochemical behavior reveals that the redox reaction of8?CPE is surface-controlled reaction. 10 crystallizes in monoclinic space group C2/m, displaying a 2?D layer structure with three unique Cd2+ centers. SO42- ions play an enormously important role in the final 2?D structure with a special coordination mode. The thermal analyses suggests that 10 is with excellent thermostability, starting degradation until 325 ℃. And the luminescent property of the compound 10 has been investigated at room temperature, revealing that it can be applied as potential fluorescent materials.