Xian-Hong Yin

Two cobalt(II) complexes based on 2-propyl-4,5-imidazoledicarboxylic acid: syntheses, crystal structures, and properties

Two complexes, [Co(H2pimdc)2(H2O)2] · 2DMF (1) and [Co(H2pimca)2(H2O)2] · 4H2O (2), have been designed, synthesized, and characterized (X-ray single crystal analysis, thermal analysis, electrochemical analysis, and infrared spectrum) based on the imidazole ligand [H3pimdc = 2-propyl-4,5-imidazoledicarboxylic acid]. Both compounds have 3-D hydrogen-bonding networks. Because of different coordination of water, 1 forms a layer-like geometry via hydrogen bonds, but 2 forms a fishingnet-like latticed geometry via hydrogen bonds.

Synthesis, crystal structures, and properties of three helical coordination polymers with quinolinecarboxylate ligand

Three mixed-ligand complexes [M(L)(Phen)(H2O)] n  · nH2O [M =  Ni (1), Co (2), Zn (3)], (L = 2-methylquinoline-3,4-dicarboxylate dianion; phen = 1,10-phenanthroline) have been synthesized by the reaction of MCl2 with 2-methylquinoline-3,4-dicarboxylate acid, sodium hydroxide, and 1,10-phenanthroline under hydrothermal conditions and were characterized by single-crystal X-ray diffraction. Complexes 1–3 crystallize isomorphously in the orthorhombic space group Pbca and feature 1-D helical chains. These helical chains are linked to form a 2-D layer through π–π stacking interactions, which are further linked by hydrogen bonds to form a 3-D network. Solid-state properties such as thermal stability and fluorescence emission of the polymeric Zn complex 3 have also been investigated.

Synthesis, characterization and luminescence properties of Eu(III) and Tb(III) complexes with novel pyrazole derivatives and 1,10-phenanthroline.

Two novel pyrazole-derived ligands, 3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinic acid (CDPA) and 3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)-N-phenylpicolinamide (CDPP) were prepared by 3,6-dichloropicolinic acid (DCPA). Their complexes with terbium(III) and europium(III) were synthesized. The complexes were characterized by elemental analysis, infrared spectra, (1)H NMR and TG-DTG. Furthermore, the above complexes using 1,10-phenanthroline as a secondary ligand were also synthesized and characterized. The luminescence properties of these complexes in solid state were investigated. The results suggested that Tb(III) complexes exhibit more efficient luminescence than Eu(III) complexes and the fluorescence of the complexes with 1,10-phenanthroline as a secondary ligand was prominently stronger than that of complexes without this ligand., and the three ligand (DCPA), (CDPP) and (CDPA) are excellent sensitizers to Eu(III) and Tb(III) ion.

Zinc(II) complexes of 4,4-oxybis(benzoate) and 2-propyl-4,5-imidazoledicarboxylic acid with bipyridine

The reactions of dicarboxylic acids, such as 4,4-oxybis(benzoic acid) [H2oba] and 2-propyl-4,5-imidazoledicarboxylate [H3pimdc], under hydrothermal conditions in the presence of an appropriate zinc salt yield two mononuclear complexes, which are characterized by elemental analysis, infrared spectrum, electrochemical analysis, thermal analysis, and X-ray crystal diffraction. Complex 1, [Zn(Hoba)2(4,4′-bpy)2], forms a 2-D supramolecular layer like rhombus via hydrogen bonds (O–H ··· N). Complex 2, [Zn(H2pimdc)2(2,2′-bpy)] · H2O, forms a zig-zag chain via multiple hydrogen bonds and C–H ··· π interactions. The moderate hydrogen-bond interactions in 1 and 2 play an important role for structural stability. The electrochemical analyses of 1 and 2 reveal electron transfer of 1 is reversible and 2 is quasi-reversible.

Crystal structure, bioactivities, and electrochemistry properties of four diverse complexes with a new pyrazole ligand

Four complexes, [Cu(cmpa)(Hpdbl)] ⋅ 2H2O (1), [Cd(cmpa)2] ⋅ 2.5H2O (2), [Cu(cmpa)2] ⋅ 2.5H2O (3), and [Pb(cmpa)2] · 2.5H2O (4), have been synthesized and characterized based on the pyrazole ligand (Hcmpa = 3-chloro-6-(3,5-dimethy-1-yl)picolinic acid, H2pdbl = pyridine-2,6-dicarboxylic acid). Complexes 1–4 showed 3-D supramolecular architectures that are connected through hydrogen bonds and aromatic π–π interactions. Preliminary antibacterial activities of the complexes indicated selective inhibition for the tested strains. The electrochemistry of 1–4 was studied by cyclic voltammetry in DMSO using a glassy carbon working electrode.

Synthesis and crystal structures of supramolecular compounds: [Cu(mpca)2(H2O)] · 3H2O and [Cu2(mpca)2(pyr)4]

A new chelate ligand, 5-methyl-1H-pyrazole-3-carboxylic acid (mpca), has been synthesized. This ligand reacts with cupric sulfate to give two supramolecular compounds [Cu(mpca)2(H2O)] · 3H2O (1) and [Cu2(mpca)2(pyr)4] (Pyr = pyridine) (2), which were characterized by elemental analysis and X-ray crystal diffraction. Helical water chain and strong π–π interaction are important for the stability of the 3-D structure of these supramolecules.

Synthesis, Structures and Properties of Two Metal-Organic Coordination Polymers Derived from Manganese(ΙΙ), Thiabendazole and Polydentate Carboxylic Acids

Two novel binuclear Mn(II) metal-organic coordination complexes [Mn2(TBZ)2(CDC)(C2O4)]n (1), {[Mn2(TBZ)2(BDC)0.5(BTC)(H2O)2]·ET}n (2), (where TBZ = thiabendazole, H2CDC = trans-1,4-cyclohexanedicarboxylic acid, H2C2O4 = oxalic acid, H3BTC = 1,3,5-benzenetricarboxylic acid, ET = ethanol, H2BDC = 1,4-benzenedicarboxylate) have been hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, electrochemical analysis and single crystal X-ray diffraction. The X-ray structure analysis reveals that 1 is s two-dimensional layer and 2 is s one-dimensional chain. In complex 1, it reveals 2-D layers composed of multi-(bidentate) bridging ligands (CDC and C2O4), and in 2, the coordinated BTC ligands adopt a monodentate mode and with BDC ligands adopt alternately chelating Mn1 and Mn2 bridges into 1-D chains. The 3-D structures of the two complexes are stabilized by π-π stacking interactions and hydrogen bonds.

Synthesis, Crystal Structure, and Properties of Two Zinc(II) Complexes With 2-propyl-4,5-imidazoledicarboxylic Acid

A tetradentate 2-propyl-4,5-imidazoledicarboxylic acid [H3pimdc] reacts with zinc sulfate in the ethanol aqueous solution and zinc acetate in the N,N-dimethylformamide (DMF) aqueous solution to give two complexes, [Zn(H2pimdc)2(H2O)2]·4H2O and [Zn(H2pimdc)2(H2O)2]·2DMF. The complexes were characterized by X-ray single-crystal analysis, thermal analysis, and IR spectrum. Because of the different coordination of water, complex 1 forms a fishing net–like latticed topology geometry via hydrogen bonds and π-π stacking interaction, but complex 2 forms a layer-like topology geometry via hydrogen bonds and π-π stacking interaction.

Synthesis, Structure, Thermal and Fluorescent Properties of a Novel Mn(II) Coordination Polymer and its Hexacyclic Water Ring

A novel Imazethapyr-bridged complex [Mn(Ima)2] (H2O)2 (1) [Imazethapyr (Ima)=5-ethyl-2-(5-isopropyl-5-methyl-4-oxo-4,5-dihydro-1H-imidazol-2-yl) nicotinic acid, has been synthesized and structurally characterized by X-ray diffraction method, infrared spectra, elemental analysis and thermal analysis. The title polymer contains a monocyclic hexamer water cluster, and the cluster plays an important role in stabilizing the complex. The fluorescence of the complex 1 in the solid state was investigated via FL55 spectrophotometer and it indicated a fluorescent behavior at room temperature.Graphical AbstractA novel Imazethapyr-bridged complex [Mn(Ima)2] (H2O)2 [Imazethapyr (Ima) = 5-ethyl-2-(5-isopropyl-5-methyl-4-oxo-4,5-dihydro -1H-imidazol-2-yl) nicotinic acid, has been synthesized and structurally characterized by X-ray diffraction method, infrared spectra, elemental analysis and thermal analysis. The title polymer contains a monocyclic hexamer water cluster, and the cluster plays an important role in stabilizing the complex.

Bis[3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinato]nickel(II) tetra-hydrate.

In the title complex, [Ni(C11H9ClN3O2)2]·4H2O, the Ni atom is coordinated by four N atoms and two O atoms derived from two tridentate 3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate ligands. The cis-N4O2 donor set defines a distorted octahedral geometry. In the crystal structure, the complex and water molecules are linked by O—H⋯O hydrogen bonds.