Yong-Hong Wen

Syntheses, structures, and fluorescent properties of four Co(II) coordination polymers based on 5-hydroxyisophthalic acid and structurally related bis(benzimidazole) ligands

Four cobalt(II) coordination polymers, {[Co(HO-BDC)(bbp)]}n (1), {[Co(HO-BDC)(bmbp)2]·(H2O)2}n (2), {[Co(HO-BDC)(bbb)]}n (3), and {[Co2(HO-BDC)2(bmbb)2]·(H2O)3}n (4), where HO-H2BDC = 5-hydroxyisophthalic acid, bbp = 1,3-bis(benzimidazol-1-yl)propane, bmbp = 1,3-bis(2-methyl-benzimidazol-1-yl)propane, bbb = 1,4-bis(benzimidazol-1-yl)butane, and bmbb = 1,4-bis(2-methyl-benzimidazol-1-yl)butane, have been synthesized and characterized by elemental analyses, IR spectra, single-crystal X-ray diffraction, thermogravimetric analyses, and fluorescence properties. Compounds 1 and 3 are 4-connected 2-D networks with (44·62) topology. Compound 2 is a 1-D chain, while 4 features a 1-D ladder. These 1-D and 2-D complexes are further connected by hydrogen bonds to form 3-D supramolecular architectures. Complexes 1–4 showed very strong yellow luminescence emission. Four new cobalt(II) coordination polymers have been synthesized and characterized by elemental analyses, IR spectra, single crystal X-ray diffraction andthermogravimetric analyses. These four complexes all showed very strong yellowluminescence emission.

Synthesis and structural characterization of lanthanide oxalate–oxydiacetate mixed-ligand coordination polymers {[Ln(oda)(H2O) x ]2(ox)} n ( x = 3 for Ln = La, Ce, Pr, Gd, Tb and x = 2 for Ln = Er)

Reactions of oxydiacetic acid (H2oda) with lanthanide oxide, nitrate, chloride, and carbonate gave six lanthanide oxalate–oxydiacetate mixed-ligand coordination polymers {[Ln(oda)(H2O) x ]2(ox)} n [x = 3 for Ln = La, Ce, Pr, Gd, Tb, (1–5), and x = 2 for Ln = Er (6)]. Oxydiacetic acid is decomposed into oxalic acid in this reaction. In the crystal structures of 1–6, oxydiacetate and the lanthanides build a chain, and the oxalate groups bridge two chains to form 1-D double-chain ladder-shaped structures, connected by intermolecular hydrogen bonds to form a 2-D network structure. These compounds contain approximately 3.0 × 6.4 Å2 channels along the c-axis. The infrared spectra and thermal behaviors of 1–6 are also investigated.

Syntheses, structures, and properties of copper and cadmium complexes with quinoline-based benzimidazole

A new tridentate ligand 2-((quinolin-8-yloxy)methyl)benzimidazole (L) and three coordination compounds, [CuLCl2] (1), [CuL(H2O)(SO4) ·  2H2O] n (2), and {[Cd2L2Cl4][CdLCl2(H2O)]2} · H2O (3), have been synthesized and characterized. Single crystal structure analyses reveal extensive intermolecular hydrogen bonding, resulting in generation of 1-D–3-D supramolecular networks. Compounds 1 and 2 constitute the first examples of Cu complexes containing both 8-hydroxyquinoline and benzimidazole, while 3 represents the first Cd complex bearing this ligand. Complexes 1–3 show similar quasi-reversible electrochemical behaviors. Complex 2 exhibits a predominantly ferromagnetic interaction between copper centers, and 3 has good fluorescence and can be used as an optical material.

Synthesis and Crystal Structure of Hexakis(imidazole) nickel (II) O,O′-diphenyldithiophosphate [Ni(Im)6](Ph2O2PS2)2

The crystal and molecular structures of [Ni(Im)6](dtp)2 (Im = imidazole, dtp = O,O′-diphenyldithiophosphate) have been determined by X-ray crystallography. It crystallizes in the triclinic system, space group Pī, with cell parameters a = 9.375 (2), b = 12.324(3), c = 13.285(3) Å, α = 107.86(3), β = 102.28(3), γ = 109.24(3), and Z = 1. The crystal structure of the title compound is built up of discrete monomeric molecules of [Ni(Im)6](dtp)2. The nickel (II) ion is hexacoordinated by six imidazole molecules and the coordination environment of Ni (II) is of octahedral geometry. In the solid state, a network of N-H∙∙∙S intermolecular hydrogen bonds connect the Ni(Im)6 moieties and O,O′-diphenyl- dithiophosphate molecules, forming a three-dimensional structure.

Synthesis, crystal structure, and properties of the cadmium complex with 2,5-bis((benzoimidazol-2-yl)methylthio)-1,3,4-thiadiazole

A cadmium complex, [Cd(L)2(CH3OH)2] · (NO3)2 (L = 2,5-bis((benzoimidazol-2-yl)methylthio)-1,3,4-thiadiazole), was synthesized and characterized by elemental analysis, infrared spectra, single-crystal and powder X-ray diffraction, UV-Vis spectra, electrochemical, and fluorescence properties. Single-crystal X-ray structure analysis reveals that the complex crystallizes in the triclinic crystal system with P space group. The coordination geometry around cadmium is octahedral. Intermolecular hydrogen bonds result in the generation of a 1-D infinite chain structure. Both UV-Vis spectra and cyclic voltammetry studies show the Cd(II) complex could be used as a probe to distinguish ssDNA from dsDNA. Differential pulse voltammetry indicates the complex could be used to analyze quantitatively for DNA. The solid complex exhibits strong luminescence emission in the visible region at room temperature upon excitation with UV radiation.

Synthesis and structural characterization of a yttrium coordination polymer formed by bridging of an acyclic polyether

The amide-type acyclic polyether, 1,2-ethylenedioxy-bis(N-pyridin-2-ylmethyl-benzamide) (L) was synthesized and characterized by EA, IR and 1H NMR spectroscopy. The reaction of yttrium nitrate with L produced a rare chain structural coordination polymer {[Y(NO3)3L(H2O)] · (H2O)} n (1) by use of the flexible ligand L as the building blocks. The structure of 1 was determined by X-ray crystallography and thermal analysis. In 1, L, as a bidentate bridging spacer, binds two neighboring Y atoms to form a one-dimensional chain polymer. The chain polymer was further connected into the three-dimensional network by hydrogen bonding interactions.

2-[(5,7-Dibromo­quinolin-8-yl)­oxy]-N-(2-meth­oxy­phen­yl)acetamide

In the title compound, C18H14Br2N2O3, an intramolecular N—H⋯N hydrogen bond forms an eight-membered ring. The dihedral angle between the planes of the quinoline system and the benzene ring is 41.69 (1)°. The crystal packing is stabilized by intermolecular C—H⋯O hydrogen bonds and short Br⋯O interactions [3.0079 (19) Å].

Syntheses, structures, and luminescent properties of lanthanide complexes with N,N′-bis(p-methoxyphenyl)-3-oxapentanediamide

An amide-type acyclic polyether, N,N′-bis(p-methoxyphenyl)-3-oxapentanediamide (L), and its three lanthanide coordination compounds, [Ln(NO3)(L)2(H2O)2] · (NO3)2 [Ln = Pr (1), Nd (2), and Dy (3)], have been synthesized and characterized by elemental analysis, IR spectroscopy, thermal analysis, and X-ray diffraction. Single crystal X-ray structure analyses reveal that 1 and 2 have the same structure and crystallize in the monoclinic crystal system with C2/c space group. The coordination geometry around the central atom is a distorted bicapped square antiprism. Extensive intermolecular hydrogen bonds in 1 and 2 result in 3-D supramolecular networks. Complex 3 exhibits luminescence in the visible region upon excitation with UV-rays.

N,N-Bis(quinolin-8-yl)-2,2'-[(1,3,4-thia-diazole-2,5-di-yl)bis-(sulfanedi-yl)]diacetamide monohydrate.

In the title compound, C24H18N6O2S3·H2O, the thiadiazole ring makes dihedral angles of 78.00 (13) and 77.27 (13)° with the quinoline ring systems. In the crystal, molecules are linked into a two-dimensional network by O—H⋯O and C—H⋯O hydrogen bonds.

Syntheses, Crystal Structures, and Fluorescent Properties of Two Mixed-Ligand Cadmium Coordination Polymers Based on Dicarboxylate and Bis-benzimidazole Ligands

AbstractTwo cadmium(II) coordination polymers, {[Cd2(HO-bdc)(Hbbop)2]}n (1), and {[Cd2(H2N-bdc)(Hbbop)2]·2(H2O)}n (2), (HO-H2bdc = 5-hydroxyisophthalic acid, H2N-H2bdc = 5-aminoisophthalic acid, and H2bbop = 1,3-bis(benzimidazol-2-yl)-2-oxapropane) have been synthesized under hydrothermal conditions and characterized by elemental analyses, IR spectra, single crystal X-ray diffraction, and thermogravimetric analyses. Their structures are 2D networks with (63) topology, which are further connected by hydrogen bonds to form 3D supramolecular architectures. Additionally, fluorescent properties of the two complexes are reported.Graphical AbstractTwo 2D mixed-ligand cadmium coordination polymers with (63) topology were synthesized and characterized.