Syntheses, Structures And Properties Investigation Of Ag(I) Coordination Polymers Based On Semi-rigid Dipyrazol Ligands And Chiral POMs

In this paper, five novel hybrid organic-inorganic materials are constructed through coordination covalent interactions utilizing transition metals/polyoxometallates (POMs) as SBUs (second building units) and N-donor organic ligands as linkers. Their structures and thermal stable properties are investigated by single crystal X-ray diffractions, elemental analysis, IR, UV-vis, TGA. Additionally, the luminescent properties of compounds 1-4 were studied. Chiral property and photo catalysis characteristic of compound 5 were also investigated in detail.1. Four Ag(Ⅰ) complexes based on 1,4-bis(di(1H-pyrazol-1-yl)methyl)benzene were synthesized under solvothermal conditions: {[Ag(μ-Lp)]NO₃}∞(1)(2) [Ag₂(Lp)1.5(NO₃)](NO₃) (3) [Ag₃(Lp)(NO₃)2(CH₃O)(CH₃OH)] (4) Compounds 1 and 2 are genuine supramolecular isomers. Single crystal X-ray analysis reveals that both of compounds 1 and 2 are built from meso-helical chains and they are the first example of meso-helical structures in the system of genuine supramolecular isomers. In these compounds, 1,4-bis(di(1H-pyrazol-1-yl)methyl)benzene ligands adopt identical chelate coordination mode in order to connect two adjacent Ag atoms into one dimensional chains. Compound 3 is two dimensional Ag(Ⅰ) complex on the basis of trinuclear silver clusters. Within this compound, four N atoms of organic linkers employ half-chelate and half-bridging connecting method, it is worth to note that the bridging coordination mode was first observed in 1,4-bis(di(1H-pyrazol-1-yl)methyl)benzene ligands. Compound 4 is a three dimensional complex constructed by 1,4-bis(di(1H-pyrazol-1-yl)methyl)benzene ligands, silver atoms and solvent molecules. In this compound, 1,4-bis(di(1H-pyrazol-1-yl)methyl)benzene ligands adopt absolute bridging coordination mode. Although masses of work about coordination polymers are reported each year, the process of self-assembly of organic-inorganic hybrid materials are still undesignable. In this paper, we successfully change the coordination mode of 1,4-bis(di(1H-pyrazol-1-yl)methyl)benzene ligands by adjusting auxiliary ligands which didn't participate the final coordination process, in order to build silver complexes on the basis of 1,4-bis(di(1H-pyrazol-1-yl)methyl)benzene ligands with different dimension. Moreover, their thermal stabilities and fluorescent properties are investigated.2. one novel polyoxometalate complex on the base of Keggin type polyoxoanion cluster decorated by Cu-PYDC coordination ion has been synthesized by convetional method: [Na₃(H₂O)11][Cu(PYDC)(H₂O)]₃[PMo₁₂O₄₀]·3H₂O (5) Compound 5 is the third case of three dimensional chiral POMs reported up to date. In this compound, each PMo12O403- anion is surrounded by six Cu-chelate PYDC cations and each Cu(Ⅱ) ion is coordinated with two Keggin type polyoxoanions, which further extend into a three dimensional chiral framework. Photo catalysis and chiral characteristics of compound 5 were studied. The synthesize of compound 5 provides a new route of building high dimensional chiral polyoxometalate complex, which increase the possibility of constructing novel chiral polyoxometalate complexes.