Search

Two ZnII-tetrazole-carboxylate coordination compounds are reported, mononuclear [Zn(atzpa)2(H2O)4] ·2H2O ( 1) and one-dimensional [Zn(atzpa)2(H2O)2] n ( 2), derived from 5-aminotetrazole-1-propanoic acid (Hatzpa). The structures of both compounds are determined by the pH value of the reaction system. The luminescence properties of Hatzpa and the compounds were investigated at room temperature in the solid state. Furthermore, differential scanning calorimetry (DSC) and thermogravimetric-differential thermogravimetric (TG-DTG) analyses were applied to evaluate the thermal decomposition behavior of such compounds. The relevant thermodynamic parameters (Δ H, Δ S, and Δ G) of the decompostion process of compound 1 were calculated, as well. [ABSTRACT FROM AUTHOR]

Reactions of Hpymtza [Hpymtza = 5-(2-pyrimidyl)tetrazole-1-acetic acid] with MnCl2 ·4H2O under different pH conditions, afforded the complexes [Mn(pymtza)2(H2O)4] ( 1) and [Mn2(pymtza)2Cl2(EtOH)] ·H2O ( 2). The compounds were structurally characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. Compound 1 shows a mononuclear structure, whereas complex 2 has a 1D chain structure. In compound 1, the pymtza ligand only acts in a monodentate manner to coordinate to one central MnII atom by one carboxylate atom, In 2, pymtza acts as tetradentate ligand to connect three MnII ions. Compounds 1 and 2 display 3D networks by hydrogen bonding interactions. Furthermore, the luminescence properties of Hpymtza as well as compounds 1 and 2 were investigated at room temperature in the solid state. [ABSTRACT FROM AUTHOR]

Reactions of the isomeric ligands Hpztza [Hpztza = 5-(2-pyrazinyl)tetrazole-2-acetic acid] and Hpmtza [Hpmtza = 5-(2-pyramidyl)tetrazole-2-acetic acid] with TbCl3 ·6H2O or DyCl3 ·6H2O under solvothermal conditions afforded four mononuclear complexes, [ Ln(pztza)2(H2O)6] ·pztza ·3H2O [ Ln = Tb ( 1), Dy ( 2)] and [ Ln(pmtza)2(H2O)6] ·Cl ·3H2O [ Ln = Tb ( 3), Dy ( 4)]. The compounds were characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. X-ray diffraction analyses reveal that all structures are mononuclear. The four compounds are self-assembled to form three-dimensional networks by hydrogen bonds. The different positions of the nitrogen atom control the coordination mode of the ligands and further influence the crystal structures. Furthermore, the luminescence properties were also investigated at room temperature in the solid state. [ABSTRACT FROM AUTHOR]

Four alkaline earth metal-organic frameworks, [Mg(H2O)6] · (pmtz)2 (1), [Ca(pmtz) 2(H2O)3] · H2O (2), [Sr(pmtz)2(H2O)4] (3), and [Ba(pmtz)2(H2O)2] · 4H2O (4) [pmtz = 5-(pyrimidyl)tetrazole anion], were synthesized and characterized by elemental analysis, IR spectroscopy, and X-ray crystallography. The crystal structures reveal that 1–3 are mononuclear while 4 displays a 2-D layer structure by bis(bidentate) bridging pmtz−. The luminescence properties of 1–4 were investigated in the solid state at room temperature. [ABSTRACT FROM AUTHOR]

Abstract: Reactions of 1H-tetrazolate-5-acetic acid(H2tza) with Nd(NO3)3·6H2O or Dy(NO3)3·6H2O with the presence of KOH under solvothermal conditions, produced two new coordination compounds, [M2(tza)3(H2O)6]·2H2O [M=Nd(1), Dy(2)]. Both compounds were structurally characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. Compounds 1 and 2 reveal 1D structures via bridging tza as linker. Furthermore, the compounds 1 and 2 showed a specific and good catalytic behavior for the polymerization of styrene, and the polymerization showed controlled characteristics. [Copyright &y& Elsevier]

A novel [Dy 4 (pytza) 5 (OH) 4 (H 2 O) 7 Cl]Cl 2 ·4H 2 O compound based on 5-(4-pyridyl)tetrazole-2-acetic acid (Hpytza) has been designed and prepared. This compound is an unprecedented two dimensional network consisting of a tetranuclear cubic [Dy 4 (OH) 4 ] 8 + secondary building unit (SBU) and tridentate pytza via the pyridine-N and the carboxylate group in a μ 1,3 -COO syn-syn bridging mode. PEG -5000 (poly(ethyleneglycol -5000 )) coated [Dy 4 (pytza) 5 (OH) 4 (H 2 O) 7 Cl]Cl 2 ·4H 2 O nanoparticles (NPs) have good dispersity in distilled water. In vitro study on Hela cells shows that such NPs show high toxicity while Hpytza is non-toxic in nature. Furthermore, such NPs can effectively inhibit the migration of Hela cells even at a low concentration, indicating their potential to inhibit the transfer of tumors in vivo . [ABSTRACT FROM AUTHOR]

An energetic material [Zn 2 (btzphda) 2 (H 2 O) 4 (dpp) 2 ]·2DMF·4H 2 O with high decomposition enthalpy of − 748.35 J/g was prepared by the reaction of H 2 btzphda, dpp and Zn(NO 3 ) 2 ·6H 2 O under solvothermal conditions, where btzphda = 1,4-bis(tetrazol-5-yl)benzene-N2,N2′-diacetato, dpp = 1.3-di(4-pyridyl)propane and DMF = N , N ′-dimethylformamide. The luminescence properties of H 2 btzphda and [Zn 2 (btzphda) 2 (H 2 O) 4 (dpp) 2 ]·2DMF·4H 2 O were investigated at room temperature in the solid state (Hitachi F4600 spectrofluorometer). Furthermore, the thermal decomposition behavior of the compound is characterized by differential scanning calorimetry (DSC) and thermogravimetric-differential thermogravimetric (TG-DTG) analyses. The entropy of activation (ΔH), enthalpy of activation (ΔS) and the free energy of activation (ΔG) for the decomposition temperature were ΔH = 250.64 kJ/mol, ΔS = 222.75 J·mol − 1 ·K − 1 and ΔG = 134.10 kJ/mol. [ABSTRACT FROM AUTHOR]