Experimental and theoretical investigations of copper (I/II) complexes with triazine-pyrazole derivatives as ligands and their in situ C-N bond cleavage.

Two copper complexes, Cu(SCN)(Mpz(∗)T-(EtO)2) (1) (Mpz(∗)T-(EtO)2=L3) and CuCl(H2O)(Mpz(∗)T-O2) (2) (Mpz(∗)T-O2=L4) were synthesized by the reaction of 2,4,6-tri(3,5-dimethylpyrazol-1-yl)-1,3,5-triazine (L1) or 2,4,6-tri(1H-pyrazol-1-yl)-1,3,5-triazine (L2) with CuCl2·2H2O in anhydrous ethanol and methanol, respectively. The complexes were characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, single crystal X-ray diffraction and X-ray powder diffraction. The structural characterizations and quantum mechanical calculations of the two complexes were analyzed in detail. It was found that an in site reaction occurred during the synthesis process of complexes 1 and 2, likely due to catalytic property of copper ions which leads to the C-N bond cleavage to generate new organic species, namely, Mpz(∗)T-(EtO)2 (L3) and Mpz(∗)T-O2 (L4).

d7 /d8 Metal Complexes Constructed from 2,6-Bis(2-benzimidazolyl)pyridyl or 2,6-Di-(pyrazol-3-yl)pyridine Derivatives: Synthesis, Structure, Characterization, and Photocatalytic Activity.

By introducing 2,6-bis(2-benzimidazolyl)pyridyl and 2,6-di-(pyrazol-3-yl)pyridine derivatives as ligand in the reaction system, three new transition-metal coordination complexes have been successfully synthesized, namely, [Co(HL1 )2 ] (1), [Ni(HL1 )2 ] (2), and [Ni3 (H2 L2 )2 ⋅(HL2 )2 ]⋅(OH)3 ⋅(Ac)⋅H2 O (3) (H2 L1 =2,6-bis(benzimidazol-2-yl)pyridine and H2 L2 =2,6-di-(5-phenyl-1H-pyrazol-3-yl)pyridine). They are all characterized by elemental analysis, IR spectroscopy, UV absorption spectroscopy, thermogravimetric analysis, powder X-ray diffraction, and single-crystal X-ray diffraction. Structural analysis shows that the structures of complexes 1 and 2 are similar. They are constructed from one metal (Co, Ni) atom and two 2,6-bis(benzimidazol-2-yl)pyridine ligands (HL1 - ); the HL1 - ligand is in the tridentate coordination mode with N3 donors. Complex 3 is a trinuclear Ni complex with four 2,6-di-(5-phenyl-1H-pyrazol-3-yl)pyridine (H2 L2 ) ligands, in which the H2 L2 possesses two coordination fashions: terminal tridentate and bridging tetradentate. In addition, the surface photovoltage spectroscopy and photocatalytic activities of complexes 1-3 were investigated in detail. The results reveal that complex 3 possesses higher photocatalytic activity.

A new metallate phase of V2O5 crystalline microstructure achieved in a facile route: synthesis, characterization, and measurement in catalytic reactions.

Experiencing a series of complicated changes, abundant orange crystals of novel metallic phase of vanadium pentoxide were obtained by a mild chemical method, the formula of which is defined as [V3(µ3-O)2⋅(µ1-OH)⋅O5]⋅H2O. Differ from the synthesis methods of vanadium oxide published, we have adopted a simple solution method that mixed starting materials are refluxing in the system of ethanol-water under a relatively lower temperature. Symmetry of the crystals is Monoclinic, with cell unit dimensions: a=4.9978(10)Å, b=8.4273(17)Å, c=7.8669(16)Å, ß=96.44(3)° and space group of P21/m. The structure of the complex was characterized by elemental analysis, IR, UV-vis spectroscopy and single-crystal diffraction analysis. Powder X-ray diffraction (PXRD) was used to detect the purity of the crystals, and crystal morphology was detected by the scanning electron microscope (SEM). In addition, in order to extend application of oxidovanadium complexes, bromination catalytic activity about the complex in a single-pot reaction of the conversion of phenol red to bromophenol blue in a mixed solution of H2O-DMF at a constant temperature of 30±0.5 °C with a buffer solution of NaH2PO4Na2HPO4 (pH=5.8) was evaluated firstly, indicating that the complex can be considered as a potential functional model of bromoperoxidase, in the meantime, we have conducted the bromination catalytic reaction to simulate and measure the changes in reaction process indirectly. Besides, catalytic oxidation activity of the complex is also evaluated in the oxidation of cyclohexane (Cy) and cyclopentane with hydrogen peroxide promoted under mild conditions, showing potential catalytic activity of the complex by comparing TON (total turnover number) ratios of CyO/CyOH (CyO is the abbreviation of cyclohexanone and CyOH represents cyclohexanol) in the oxidation results.

A family of uranyl-aromatic dicarboxylate (pht-, ipa-, tpa-) framework hybrid materials: photoluminescence, surface photovoltage and dye adsorption.

Four uranyl complexes [(UO2)(pht)H2O]·H2O (pht = phthalic acid) (1), (UO2)2(Hipa)4(H2O)2 (Hipa = isophthalic acid) (2), (UO2)(tpa)(DMF)2 (tpa = terephthalic acid) (3) and (UO2)(box)2 (box = benzoic acid) (4) were synthesized by the reaction of UO2(CH3COO)2·2H2O as the metal source and phthalic acid, isophthalic acid, terephthalic acid or benzoic acid as the ligand. They were characterized by elemental analyses, IR, UV-Vis, XRD, single crystal X-ray diffraction analysis and thermal gravimetric analysis. The structural analysis reveals that complex 1 exhibits a one-dimensional chain structure constructed by the building unit [(UO2)2(pht)4(H2O)2] and further extends the chain into a 2D supramolecular architecture by hydrogen bonding interactions. Complex 2 is a discrete [(UO2)2(Hipa)4(H2O)2] structure, and by the hydrogen bonding interaction, forms a 3D supramolecular structure. In complexes 3 and 4, adjacent uranyl polyhedra form a 1D chain through bridging terephthalic acid and benzoic acid, respectively. In order to extend their functional properties, their photoluminescence, surface photovoltage and dye adsorption properties have been studied.