Two dinuclear copper(II) coordination polymers constructed from m-hydroxybenzoic acid and N-donor ligands: synthesis, crystal structures, and magnetic properties

Crystal structure and Hirshfeld surface analysis of a new mononuclear copper(II) complex: [bis-(pyridin-2-yl-κN)amine](formato-κO)(m-hy-droxy-benzoato-κ2O,O')copper(II)

A new mononuclear copper(II) complex, [Cu(C7H5O3)(HCO2)(C10H9N3)], containing mixed N- and O-donor ligands, 2,2'-di-pyridyl-amine (dpyam) and m-hy-droxy-benzoate (m-OHbenz), has been obtained from a solvent mixture. The coordination environment of the CuII ion is distorted square-pyramidal with a [N2O3] coordination set originating from the chelating dpyam and m-OHbenz ligands in the basal plane and the O atom of a formato ligand at the apical position. The crystal structure of the title complex is stabilized by N-H⋯O, O-H⋯O, C-H⋯O hydrogen-bonding, π-π and C-H⋯π inter-molecular inter-actions, which were qu-anti-fied by Hirshfeld surface analysis.

Synthesis, crystal structures and fluorescence properties of two 1D Zn(II) homologous coordination polymers

A pair of zinc(II)-based one-dimensional (1D) homologous coordination polymers, [Zn(Hdba)2(bib)] n (1) and [Zn(Hdba)2(bmib)] n (2), where H2dba = 3-hydroxybenzoic acid, bib = 1,4-bis(1-imidazolyl)benzene, and bmib = 1,4-bis(2-methyl-1H-imidazol-1-yl)benzene were hydrothermally synthesized and characterized through infrared spectroscopy (IR), elemental and thermal analysis (EA), powder X-ray diffraction (PXRD), and single-crystal X-ray diffraction (SCXRD) analyses. The results revealed that 1 and 2 have the same zigzag infinite chain framework through the partially deprotonated Hdba– monodentate linkage and with μ 2-bib bridging the Zn(II) atoms in 1, and with μ 2-bmib bridges for the Zn(II) atoms in 2. For both 1 and 2, each zinc atom has a slightly twisted tetrahedral configuration with a N2O2 donor set. These chains of 1 and 2 are further connected into three-dimensional (3D) supramolecular structures through O–H···O, C–H···O hydrogen bonds and π···π, C–H···π stacking interactions for 1, and O–H···O, C–H···O hydrogen bonds for 2. Topologically, the 3D hydrogen-bonded organic framework or the 2D π-stacking structure of 1 can be simplified as a 4-connected dia Diamond type with a Schläfli symbol {66}, or as a 4-connected sql type with a Schläfli symbol {44·62} and a Shubnikov tetragonal plane net. The thermal stability and the solid-state fluorescence properties of 1 and 2 were investigated.

Crystal structure of a novel one-dimensional zigzag chain-like cobalt(II) coordination polymer constructed from 4,4'-bi-pyridine and 2-hy-droxy-benzoate ligands

The synthesis, crystal structure and physical properties of a novel one-dimensional zigzag chain-like Co^II coordination polymer, [Co₂(2-OHbenz)₄(4,4′-bpy)_2.5(H₂O)]_n, constructed from 4,4′-bi­pyridine (4,4′-bpy) and 2-hy­droxy­benzoate (2-OHbenz) are reported.

A novel one-dimensional zigzag chain-like Co^II coordination polymer constructed from 4,4′-bi­pyridine (4,4′-bpy) and 2-hy­droxy­benzoate (2-OHbenz) ligands, namely, catena-poly[[(4,4′-bi­pyridine-κN)­(μ-2-hy­droxy­benzoato-κ²O:O′)(2-hy­droxy­benzoato-κ²O,O′)cobalt(II)]-μ-4,4′-bi­pyridine-κ²N:N′-[aquahemi(μ-4,4′-bi­pyridine-κ²N:N′)(2-hy­droxy­benzoato-κO(2-hy­droxy­benzoato-κ²O:O′)cobalt(II)], [Co₂(C₇H₅O₃)₄(C₁₀H₈N₂)_2.5(H₂O)]_n, has been synthesized by reacting cobalt(II) nitrate trihydrate, 4,4′-bpy and 2-hy­droxy­benzoic acid in a mixture of water and methanol at room temperature. There are two independent Co^II centers, Co1 and Co2, in the asymmetric unit, revealing a distorted octa­hedral geometry with chromophore types of [CoN₂O₄] and [CoN₂O₃O′], respectively. The Co1 ions are doubly bridged by 2-OHbenz ligands with syn–anti coordination mode, generating a dinuclear unit. The bridging 4,4′-bpy ligands connect these dinuclear units and the mononuclear Co2 chromophores, providing a one-dimensional alternating zigzag chain-like structure. In the crystal, inter­molecular hydrogen bonds, C—H⋯π and π–π stacking inter­actions are observed and these help to consolidate the packing. In addition, the physical properties of the title compound are reported.