Heterocyclic Metal Complexes Of Chiral Schiff Base Complexes Synthesis, Structure And Characterization

A total of nine new complexes have been designed and synthesized by using transition and rare earth metal ions as coordinated center, with pyridine carboxyl, tetrazole, Schiff base and cyanometallic anions as bridged ligands. Their crystal structures were determined by X-ray single crystal diffractometer, and some properties of those complexes have been characterized by IR, TG-DTA and spectrofluorophotometer.1. Utilizing 2, 2'-bipyridine-3, 3'-dicarboxylic acid 1, 1'-dioxide [(R, S)-H2BDCD] and CuCl₂·2H₂O (or Ba(NO₃)₂·6H₂O) under hydrothermal condition produce two novel three dimensional coordination polymers {[Cu(BDCD)2]·H₂O}n, 1 and [Ba(BDCD)₂·2H₂O] n, 2. X-Ray Crystallography Measurements reveals that compound 1 contain many kinds of interesting nano-cavities,and compound 2 exhibits a novel binuclear Ba2+ core.2. Obtained two 3d-4f heterometallic polymeric complex {[Nd2Cu2(L)2 (OXA)4·2(2H₂O)]·2(3H₂O)}n,3 and {[EuCu(bpdc)2·4(H₂O)I)]·2H₂O}n, 4 from hydrothermal reaction in the presence of ethanol and water. X-ray single crystal diffraction investigation of the polymeric complexes {[Nd2Cu2 (L)₂(OXA)₄·2(2H₂O)]·2(3H₂O)}_n,3 exhibits an interesting and novel topological structure. The local coordination environments around the Nd center can be best described as a slightly distorted three face centered trigonal prism which is connected by six oxygen atoms from three different oxalate ligands through monodentate coordination modes, one oxygen atom from the carboxylic group of 2, 2'-bipyridine-3-cayboxylate ligand and double water molecules. Another metal center Cu1 adopts a slightly distorted square pyramidal coordination mode, in which the square plane was defined by double oxygen atoms from different carboxylate groups of the same oxalate liagnd, double nitrogen atoms from 2, 2'-bipyridine-3-cayboxylate. All the 2, 2'-bipyridine-3-cayboxylate ligands acting as tetradentate ligands link double different Cu atoms and one Nd atom, thus resulting in the formation of a 1D ladder-like structure along the c-axis. Interestingly, the oxalate ligands can be classified as two types according to the coordination modes of carboxylate. Part of them as tetradentate ligands link different Cu and Nd atoms through forming double five-member rings, and others as tetradentate ligands link different Nd atoms also through forming double five-member rings. Single-crystal X-ray diffraction analysis reveals that complex {[EuCu(bpdc)₂·4(H₂O)I)]·2H₂O}n, 4 is interconnected by Eu³⁺ through carboxylic groups to produce a linear 1D structure along a direction, then through Cu²⁺ chelating double nitrogens of bpdc2- ligand along b direction to form the 2D Cu²⁺-Eu³⁺ heterometallic-organic framework.3. Heat treatment (refluxing) a mixture of fipronil, sodium azide and CuCl₂ in the mixed solvent of ethanol and water gave complex 4, [Cu(L)₂](H₂O)₂]·2H₂O. Hydrothermal reaction of fipronil, sodium azide and Cd(ClO4)2 in the presence of water and ethanol (Demko-Sharpless tetrazole synthesis methods) yields complex 5, [Cd(L)₂](H₂O)₂]·2H₂O. X-Ray Crystallography Measurements reveals that the center metals in both complexes are six coordinated which connected by two water molecules, two nitrogen atoms from different tetrazolyl groups and two nitrogen atoms from pyrazolyl groups respectively. So the central metal atom in both the complexs adopts a distorted octahedral coordination mode. In complex 4, CuII lies on a two fold rotation axis made up of double tetrazole ligands and two coordinated water molecules. Interestingly, many different hydrogen bonds and weak supramolecular interactions involvesπ-πstacking can be found in both compounds, important in supramolecular assembly and stabilization of the compounds.4. Utilizing Cu²⁺ and the Schiff base derived from 2,6-dimethylphenyl-4-methylphenol and 2-Aminobutanol produce two coordination clusters [Cu(MBD)₂(N₃)₆], 6 and [Cu(MBD)Cl₄], 7. X-Ray Crystallography Measurements reveals that compound 6 contains unusual six nuclear and compound 7 exhibits a binuclear Cu²⁺ core. Schiff base derived from 2,6-dimethylphenyl-4-methylphenol and 2-amine-1-butanol acting as polydentate ligand by phenolichydroxyl oxygen atoms, alcoholichydroxyl oxygen atoms and nitrogen atom coordinates to copper atoms. In compound 6, there are two kinds of coordination modes around Cu center: five coordinated and four coordinated.5. {2Cu (DMCL)₂·[Fe(CN)₆]}n·2H₂O was synthesized by the reaction of 1,2-Diaminocyclohexane, Cu(ClO₄)2 and [BuN]3[Fe(CN)6]. X-Ray Crystallography Measurements reveals that it contains two bridgingspaces:μ4 bridging mode andμ2 bridging mode. the four Cu which coordinated to the same [Fe(CN)₆]3- lie in the same plane, and the two planes of ligands connecting to the adjacent cyanide is nearly vertical. But the planes of ligands connecting to the para-position cyanide are almost parallel, as well as in 2-bridging mode.6. Explored the impact of intermolecalar force, auxiliary ligand, molecular configuration and coordination model of ligand on the entire structure of the coordination complexes and the relationship between structural feature and chemical physical properties of the products.