Xiu-Ying Li

Synthesis, structure and characterization of two Cd(II) coordination polymers with helical structures

Two coordination polymers, [Cd2Cl2(1,3-BDC)(TTBT)(H2O)] (1) and [CdCl(1,4-HBDC)(TTBT)] (2) (1,3-BDC = 1,3-benzenedicarboxylate, 1,4-BDC = 1,4-benzenedicarboxylate, and TTBT = 10,11,12,13-tetrahydro-4,5,9,14-tetraaza-benzo[b]triphenylene), have been prepared under hydrothermal conditions and characterized by elemental analyses, IR spectra, thermal gravimetry (TG), fluorescence emission and single crystal X-ray diffraction analyses. The crystal structures were determined by X-ray diffraction and refined by full-matrix least-squares methods to R = 0.0621 and wR = 0.1543 using 4937 reflections with I > 2σ(I) for 1; and R = 0.0525 and wR = 0.1427 using 3386 reflections with I > 2σ(I) for 2. Compound 1 possesses a chiral chain structure. Adjacent chiral chains are further linked through π–π interactions between TTBT ligands to give a three-dimensional supramolecular architecture. Compound 2 displays a helical chain structure, with neighboring chains stacked by π–π interactions, generating an unusual three-dimensional supramolecular structure.

Syntheses, crystal structures, and characterization of three metal–organic complexes with 2,2′-biphenyldicarboxylic acid and phenanthroline ligands

Three complexes constructed with 2,2′-biphenyldicarboxylic acid, multidentate nitrogen donors, and metal salts, {[Cd(2,2′-dpdc)(tppp)(H2O)]2 · 2H2O} n (1), {[Pb(2,2′-dpdc)(pyphen)]2} n (2), and {[Pb(2,2′-dpdc)(dppz)]} n (3) (H2dpdc = 2,2′-diphenyldicarboxylic acid; tppp = 4-(1H-1,3,7,8-tetraazacyclopenta[l]phenanthren-2-yl)phenol; pyphen = pyrazino[2,3-f]-[1,10]phenanthroline; and dppz = dipyrido[3,2-a:2′,3′-c]phenazine), are synthesized under hydrothermal conditions. These complexes are characterized by single-crystal X-ray diffraction, elemental analysis, IR, TGA, and photoluminescence. In 1, two 2,2′-dpdc ions bridge two Cd(II) ions to form an isolated cluster with Cd ··· Cd distance of 5.023(4) Å. These clusters are further linked by intermolecular hydrogen bonds, yielding a 2-D supramolecular structure. Complex 2 contains two crystallographically independent Pb(II) ions in the asymmetric unit. Pb1 ions are bridged by 2,2′-dpdc anions to form a chain along the x-axis. Two Pb2 ions are coordinated by two 2,2′-dpdc anions and two pyphen ligands to form a cluster. These clusters are linked by π–π interactions to yield a 1-D supramolecular chain along the y-axis. In 3, neighboring Pb(II) atoms are bridged by 2,2′-dpdc anions to form a 1-D chain structure. Further, the chains are linked into a 3-D supramolecular network through aromatic π–π interactions.

Bis[3,5-difluoro-2-(2-pyrid-yl)phen-yl](picolinato)iridium(III).

The Ir centre in the title complex, [Ir(C11H6F2N)2(C6H4NO2)], is six-coordinated in a slightly distorted octahedral IrC2N3O fashion.

Syntheses and characterization of four coordination compounds derived from 10,11,12,13-tetrahydro-4,5,9,14-tetraaza-benzo[b]triphenylene and benzene-dicarboxylic acids

[Co2(TTBT)4(1,2-BDC)2] n  · 4nH2O (1), [Pb2(TTBT)2(1,3-BDC)2] n  · nTTBT · 2nH2O (2), [Fe(TTBT)(1,4-BDC)(H2O)] n (3), and [Zn(TTBT)(1,4-BDC)(H2O)] n (4) have been hydrothermally synthesized by self-assembly of TTBT (TTBT = 10,11,12,13-tetrahydro-4,5,9,14-tetraaza-benzo[b]triphenylene), benzene-dicarboxylic acid ligands 1,2-H2BDC, 1,3-H2BDC or 1,4-H2BDC (1,2-H2BDC = 1,2-benzenedicarboxylic acid, 1,3-H2BDC = 1,3-benzenedicarboxylic acid, 1,4-H2BDC = 1,4-benzenedicarboxylic acid), and various metal salts. Compound 1 has dinuclear cluster units, four dimeric Co2 units connected to form a 32-membered ring via weak offset π–π interactions, which are further stacked via strong π–π interactions to form a 3-D supramolecular framework. Complex 2 contains 2-D layers with rhombohedral grids, which are connected to a 3-D structure by π–π interactions. 3 and 4 feature 1-D infinite chains, which are further extended by strong π–π interactions and O–H···O hydrogen bonds resulting in 3-D supramolecular architectures. The photoluminescent properties of 2 and 4 have also been investigated.

Hydrothermal syntheses, structural characterization, and photoluminescent properties of five lanthanide coordination polymers

Five mixed-ligand coordination polymers, [Ln2(PTCP)2(m-BDC)3] n  · nH2O (Ln = Pr (1), Sm (2), Eu (3), Tb (4), Dy (5); m-BDC = 1,3-benzenedicarboxylate; PTCP = 2-phenyl-1H-1,3,7,8-tetraazacyclopenta[l]phenanthrene), were synthesized and characterized by IR spectra, elemental analyses, thermogravimetric analyses, single-crystal X-ray diffraction, and solid-state photoluminescent spectra. X-ray crystallographic analyses reveal that the five complexes are 1-D structures based on dinuclear [Ln2O12N4] units and further assembled into 3-D supramolecular networks by hydrogen bonds and π···π stacking interactions. The solids possess high thermal stabilities, with 3 and 4 exhibiting strong pure red and green characteristic emissions of Eu(III) and Tb(III) at room temperature.

catena-Poly[[aqua­(dipyrido[3,2-a:2′,3′-c]phenazine-κ2N4,N5)iron(II)]-μ-pyrazine-2,3-dicarboxyl­ato-κ3N1,O2:O3]

In the title compound, [Fe(C6H2N2O4)(C18H10N4)(H2O)]n, the FeII ion adopts a slightly distorted octahedral mer-FeN3O3 geometry, arising from one N,N′-bidentate dipyrido[3,2-a:2′,3′-c]phenazine ligand, one N,O-chelating pyrazine-2,3-dicarboxylate dianion and one water molecule. An O-bonded symmetry-related dianion completes the coordination of the metal. The bridging dianion results in a one-dimensional polymeric chain. Aromatic π–π stacking interactions between ligands [centroid–centroid separations = 3.528 (2) and 3.741 (2) Å] and O—H⋯O and O—H⋯N hydrogen bonds link the chains together, leading to a three-dimensional supramolecular network.

Detection of nonfluorescent cyhalothrin in honey by a spheral SiO2-based particle coating with thin fluorescent molecularly imprinted polymers film

In this study, we report a general protocol for making core–shell SiO2@KH570-MIP based on the surface modification of SiO2 beads for the selective detection of ultra trace cyhalothrin. We first prepared the fluorescent surface molecularly imprinted polymer (SMIP) spheres via copolymerization of acrylamide with allyl fluorescein in the presence of cyhalothrin to form recognition sites. The experimental results showed that the fluorescence quenching of SiO2@KH570-MIP for cyhalothrin was much higher than that of the structural analogue composite, which illustrated good recognition capacity and selectivity of SiO2@KH570-MIP for the template. In addition, a linear relationship could be obtained at a lower concentration range of 0–2.5 nM with a correlation coefficient of 0.99698 described by the Stern–Volmer equation. The results of practical detection suggest that the developed method satisfactorily determines cyhalothrin in honey samples. This study therefore demonstrated the potential of SiO2-based SMIP spheres for the recognition and detection of cyhalothrin in food.

Hydrothermal Syntheses and Crystal Structures of Three Zn(II) Coordination Compounds Constructed with 3,5-Pyrazoledicarboxylic Acid

Three novel metal–organic coordination compounds, [Zn(Hdcp)(H2O)4]·1.5H2O (1), [Zn(Hdcp)(H2O)2]∞ (2) and [Zn3(dcp)2(H2O)5]∞ (3) with the ligand 3,5-pyrazoledicarboxylic acid were prepared by the hydrothermal method. The complexes were structurally characterized by elemental analysis, IR spectroscopy and X-ray single-crystal diffraction. Compound 1 is a mononuclear molecule that is linked into a 3D supramolecular framework via N–H···O and O–H···O hydrogen bonds. In 2, two types of carboxylic bridges were found between ZnII ions to form a 1D double-chain. The 1D chains were further construct into a 3D structure by hydrogen bonds. Trinuclear 3 consists of 1D bi-infinite parallelogram chains of [Zn3(dcp)2(H2O)3] trimers. In the basic trinuclear unit a further bridging mode of the ligand is seen where two dcp3− ligands chelate three ZnII ions by utilizing five donors of the dcp3− ligand. The photoluminescent properties of 1, 2 and 3 were investigated.

Chlorido(10,11,12,13-tetra-hydro-4,5,9,14-tetra-aza-benzo[b]triphenyl-ene-κN,N)copper(I).

The CuI atom in the title compound, [CuCl(C18H14N4)], is N,N′-chelated by the N-heterocyclic ligand and coordinated by one Cl− anion in a distorted trigonal geometry. In the crystal, the CuI atom is disordered over two positions in a 0.667 (6):0.333 (6) ratio. The deviation of the Cu atom from the N/N/Cl coordination plane is 0.013 (3) Å for the major component and 0.073 (6) Å for the minor component. Two methylene C atoms are also disordered over two positions in a 0.667 (6):0.333 (6) ratio.

Bis(imidazo[4,5-f][1,10]phenanthroline)dinitratolead(II)

In the title compound, [Pb(NO3)2(C13H8N4)2], the PbII atom (site symmetry 2) is hexacoordinated by four N atoms from two N,N′-bidentate imidazo[4,5-f][1,10]phenanthroline (L) ligands and two O atoms from two weakly coordinated nitrate ions [Pb—O = 2.872 (5) Å] in an irregular arrangement, which may be ascribed to the stereochemically active lone pair of electrons on the metal ion. In the crystal, intermolecular bifurcated N—H⋯(O,O) hydrogen bonds connect the molecules into chains propagating along [100]. Adjacent chains interact by strong aromatic π–π stacking interactions, with a centroid–centroid distance of 3.483 (2) Å.