Synthesis, Structure and Surface Photovoltage of a Series of NiII Coordination Polymers

From 1D Coordination Polymers to Metal Organic Frameworks by the Use of 2-Pyridyl Oximes

The synthesis and characterization of coordination polymers and metal-organic frameworks (MOFs) has attracted a significant interest over the last decades due to their fascinating physical properties, as well as their use in a wide range of technological, environmental, and biomedical applications. The initial use of 2-pyridyl oximic ligands such as pyridine-2 amidoxime (H2pyaox) and 2-methyl pyridyl ketoxime (Hmpko) in combination with 1,2,4,5-benzene tetracarboxylic acid (pyromellitic acid), H4pma, provided access to nine new compounds whose structures and properties are discussed in detail. Among them, [Zn2(pma)(H2pyaox)2(H2O)2]n (3) and [Cu4(OH)2(pma)(mpko)2]n (9) are the first MOFs based on a 2-pyridyl oxime with 9 possessing a novel 3,4,5,8-c net topology. [Zn2(pma)(H2pyaox)2]n (2), [Cu2(pma)(H2pyaox)2(DMF)2]n (6), and [Cu2(pma)(Hmpko)2(DMF)2]n (8) join a small family of coordination polymers containing an oximic ligand. 9 exhibits selectivity for FeIII ions adsorption, as was demonstrated by a variety of techniques including UV-vis, EDX, and magnetism. DC magnetic susceptibility studies in 9 revealed the presence of strong antiferromagnetic interactions between the metal centers, which lead to a diamagnetic ground state; it was also found that the magnetic properties of 9 are affected by the amount of the encapsulated Fe3+ ions, which is a very desirable property for the development of magnetism-based sensors.

Effects of N-oxidation on the molecular and crystal structures and properties of isocinchomeronic acid, its metal complexes and their supramolecular architectures: experimental, CSD survey, solution and theoretical approaches

A series of new coordination complexes bearing H₂pydco, an O-donor ligand, were synthesized and compared to corresponding complexes with H₂pydc. The molecular and supramolecular structures were investigated using crystallography, solution phase and high level DFT studies.

Photoelectric properties and potential nitro derivatives sensing by a highly luminescent of Zn(ii) and Cd(ii) metal–organic frameworks assembled by the flexible hexapodal ligand, 1,3,5-triazine-2,4,6-triamine hexaacetic acid

The luminescent quenching of coordination polymers 1 and 2 were especially obvious with the increasing of the nitro derivatives concentration, indicating 1 and 2 have very high sensitivity sensing properties.

Nickel-catalyzed release of H2 from formic acid and a new method for the synthesis of zerovalent Ni(PMe3)4

Ni(PMe₃)₄, which can be obtained by reaction of either Ni(py)₄(O₂CH)₂ or Ni(O₂CH)₂·2H₂O with PMe₃, serves as a catalyst for the release of H₂ from formic acid.

A family of uranium–carboxylic acid hybrid materials: synthesis, structure and mixed-dye selective adsorption

The synthesis, structure, photoluminescence, surface photovoltage and mixed-dye selective adsorption of four uranyl complexes have been studied.

Novel photochromic infinite coordination polymer particles derived from a diarylethene photoswitch

A novel infinite coordination polymer (DAE-ICP) based on zinc nitrite and a diarylethene photoswitch, with reversible photochromic properties in solution and the solid state upon applying photostimuli, was synthesized and characterized by FT-IR, EDX, FE-SEM and FE-TEM.

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

The synthesis, structure, photoluminescence, surface photovoltage and dye adsorption have been studied.

Two Zn(II) mononuclear coordination compounds with pyridinedicarboxylate and auxiliary N-(pyridin-4-ylmethylidene)hydroxylamine ligands

Two new mononuclear coordination compounds, bis{4-[(hydroxyimino)methyl]pyridinium} diaquabis(pyridine-2,5-dicarboxylato-κ(2)N,O(2))zincate(II), (C6H7N2O)2[Zn(C7H3NO4)2(H2O)2], (1), and (pyridine-2,6-dicarboxylato-κ(3)O(2),N,O(6))bis[N-(pyridin-4-ylmethylidene-κN)hydroxylamine]zinc(II), [Zn(C7H3NO4)(C6H6N2O)2], (2), have been synthesized and characterized by single-crystal X-ray diffractometry. The centrosymmetric Zn(II) cation in (1) is octahedrally coordinated by two chelating pyridine-2,5-dicarboxylate ligands and by two water molecules in a distorted octahedral geometry. In (2), the Zn(II) cation is coordinated by a tridentate pyridine-2,6-dicarboxylate dianion and by two N-(pyridin-4-ylmethylidene)hydroxylamine molecules in a distorted C2-symmetric trigonal bipyramidal coordination geometry.

Enhanced photovoltaic performance of Cu-based metal-organic frameworks sensitized solar cell by addition of carbon nanotubes

In the present work, TiO₂ nanoparticle and multi-walled carbon nanotubes composite powder is prepared hydrothermally. After doctor blading the paste from composite powder, the resulted composite film is sensitized with Cu-based metal-organic frameworks using a layer-by-layer deposition technique and the film is characterized using FE-SEM, EDX, XRD, UV/Visible spectrophotometry and photoluminescence spectroscopy. The influence of the carbon nanotubes in photovoltaic performance is studied by constructing a Grätzel cell with I₃⁻/I⁻ redox couple containing electrolyte. The results demonstrate that the introduction of carbon nanotubes accelerates the electron transfer, and thereby enhances the photovoltaic performance of the cell with a nearly 60% increment in power conversion efficiency.

Three novel d7/d10 metal complexes with N-heterocyclic ligand of 2,6-bis(3-pyrazolyl)pyridine: synthesis, structure, surface photovoltage spectroscopy and photocatalytic activity

We synthesized three novel d⁷/d¹⁰ metal complexes with 2,6-bis(3-pyrazolyl)pyridine and studied their surface photovoltage spectra and photocatalytic activities.

Syntheses, characterization, antimicrobial and cytotoxic activities of pyridine-2,5-dicarboxylate complexes with 1,10-phenanthroline

In this study, four mononuclear M(II)-pyridine-2,5-dicarboxylate (M = Co(II), Ni(II), Cu(II) and Zn(II) complexes with pyridine-2,5-dicarboxylic acid or isocinchomeronic acid, 1,10-phenanthroline (phen), [Co(Hpydc)(2)(phen)]·H(2)O (1), [Ni(pydc)(phen)(2)]·6.5H(2)O (2) [Cu(pydc)(phen)(H(2)O)(2)] (3) and [Zn(pydc)(phen)(H(2)O)(2)]·H(2)O (4) have been synthesized. Elemental, thermal and mass analyses, molar conductance, magnetic susceptibilities, IR and UV/vis spectroscopic studies have been performed to characterize the complexes. Subsequently, these ligands and complexes were tested for antimicrobial activity by disc diffusion method on Gram positive, negative bacteria and yeast. In addition, cytotoxic activity tests were performed on rat glioma (C6) cells by MTT viability assay for 24 and 48 h. Antimicrobial activity results demonstrated that when compared to the standard antibiotics, phen displayed the most effective antimicrobial effect. The effect of synthesized complexes was close to phen or less. Cytotoxic activity results showed that IC(50) value of phen was determined as 31 μM for 48 h. (1) and (2) compared to the alone ligand had less toxic activity. IC(50) values of (3) for 24 and 48 h treatments were 2.5 and 0.6 μM, respectively. IC(50) value of (4) for 48 h was 15 μM. In conclusion, phen, (3) and (4) may be useful as antibacterial and antiproliferative agents in the future.

Synthesis, structure and photophysical properties of two transitional metal supramolecular complexes

Two supramolecular complexes: [Co(2,6-PDC)(Hdmpz)3]·H2O (1) and [Zn(2,6-PDC)(Hdmpz)2] (2) {2,6-PDC=pyridine-2,6-dicarboxylic acid, Hdmpz=3,5-dimethylpyrazol}, self-assembles via O-H⋯O and N-H⋯O hydrogen bondings into supramolecular networks, which are characterized by elemental analyses, IR spectra and single crystal X-ray diffraction analysis. Both of them consist of two-dimensional networks that are stacked together by typical hydrogen bonding interactions (i.e. O-H⋯O and N-H⋯O), which often play important roles in the formation of low-dimensional into high-dimensional supramolecular networks. In addition, quantum chemistry calculations and surface photovoltage spectroscopy are performed firstly with the complexes.