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Chun-Ying Duan

Publications and source records attributed to Chun-Ying Duan.

11 recordsLinked to original sources
PubMed2006

Quinoline-based molecular clips for selective fluorescent detection of Zn2+.

New selective Zn2+ fluorescent sensors, di(2-quinoline-carbaldehyde)-2,2'-bibenzoyl-hydrazone (QB1) and di(2-quinolinecarbaldehyde)-6,6'-dicarboxylic acid hydrazone-2,2'-bipyridine (QB2), have been designed and prepared. Both QB sensors exhibit an emission band centered at 405 nm (excitation at 350 nm) with low quantum yield. Zinc binding not only red-shifts the emission band to 500 nm, but also enhances the fluorescence intensity by an order of magnitude based on the deprotonization strategy via self-assembly. These probes are highly selective for Zn2+ over biologically relevant alkali metals, alkaline earth metals and the first row transition metals such as Mn2+, Fe2+, Co2+ and Ni2+ in buffered aqueous DMSO solution.

Journal Article↗
PubMed2006

Chromium(III) complexes of D-glucosaminic acid and their effect on decreasing blood sugar in vivo.

Two chromium(III) complexes of glucosaminic acid were synthesized by neutralization and exchange reaction. The formation of 1 : 1 and 2 : 3 (Cr : glucosaminate) complexes was confirmed by elemental analyses and spectroscopic studies. The effect of the complexes on decreasing blood sugar was investigated on type-2 diabetes model rats induced by tetraoxypyrimidine. The results indicated that the effect on decreasing blood sugar was comparable to that of picolinate chromium complex (Cr(pic)(3)) currently used world wide.

Alloxan↗
PubMed2005

1D helix, 2D brick-wall and herringbone, and 3D interpenetration d10 metal-organic framework structures assembled from pyridine-2,6-dicarboxylic acid N-oxide.

Five novel interesting d(10) metal coordination polymers, [Zn(PDCO)(H2O)2]n (PDCO = pyridine-2,6-dicarboxylic acid N-oxide) (1), [Zn2(PDCO)2(4,4'-bpy)2(H2O)2.3H2O]n (bpy = bipyridine) (2), [Zn(PDCO)(bix)]n (bix = 1,4-bis(imidazol-1-ylmethyl)benzene) (3), [Zn(PDCO)(bbi).0.5H2O]n (bbi = 1,1'-(1,4-butanediyl)bis(imidazole)) (4), and [Cd(PDCO)(bix)(1.5).1.5H2O]n (5), have been synthesized under hydrothermal conditions and structurally characterized. Polymer 1 possesses a one-dimensional (1D) helical chainlike structure with 4(1) helices running along the c-axis with a pitch of 10.090 Angstroms. Polymer 2 has an infinite chiral two-dimensional (2D) brick-wall-like layer structure in the ac plane built from achiral components, while both 3 and 4 exhibit an infinite 2D herringbone architecture, respectively extended in the ac and ab plane. Polymer 5 features a most remarkable and unique three-dimensional (3D) porous framework with 2-fold interpenetration related by symmetry, which contains channels in the b and c directions, both distributed in a rectangular grid fashion. Compounds 1-5, with systematic variation in dimensionality from 1D to 2D to 3D, are the first examples of d(10) metal coordination polymers into which pyridinedicarboxylic acid N-oxide has been introduced. In addition, polymers 1, 4, and 5 display strong blue fluorescent emissions in the solid state. Polymer 3 exhibits a strong SHG response, estimated to be approximately 0.9 times that of urea.

Journal Article↗
PubMed2005

Heterometallic compounds assembled from ferrocene-containing bisthiosemicarbazone clips.

Heteropolynuclear organometallic compounds have been constructed by using the ferrocene-based ligand H(2)L, [NH(2)SCNHN=C(CH(3))(C(5)H(4))](2)Fe. Reaction of the ligand H(2)L with the cobalt(II) salt gave a tetranuclear helicate Co(2)Fe(2) (1) with two ferrocene-based clips wrapped around the two cobalt atoms. The chiral helicates recognized the neighbors with same chirality through intermolecular hydrogen bonding between the thiosemicarbazone moieties to form a one-dimensional chiral channel. Reaction of the ligand H(2)L with the cadmium(II) salt afforded a tetranuclear dimeric compound Cd(2)Fe(2) (2), with two symmetric related parts bridged through two sulfur atoms. Reaction of the ligand H(2)L with the copper(I) salt, in the presence of triethylamine, resulted in a hexanuclear compound Cu(4)Fe(2) (3) with a crownlike Cu(4)S(4) octagon similar to that of S(8) sited inside and two ferrocene-containing ligands positioned outside. Electrochemical measurements were displayed to investigate the redox communications between the ferrocene moieties through metal centers.

Cadmium↗
PubMed2005

Enantiomeric interpenetrating 3D nets with chiral silver helicates.

A new enantiomeric interpenetrating 3D nets with chiral helical coordination silver(i) polymer was achieved via self-assembly using the new ligand modular approach, in which the special helical conformation of the ligand provided the opportunity to translate chirality from one metal center to others.

Ligands↗
PubMed2004

A study on oxygen insertion in dinuclear silver cryptates.

Two novel silver(I) cryptates are reported in this paper. [Ag(2)(L(1)O)](ClO(4))(2).H(2)O and [Ag(2)L(1)](ClO(4))(2).1.5H(2)O were synthesized by the condensation of tris (3-aminopropyl) amine with m-phthalaldehyde in the presence of silver(i) ion, under aerobic and anaerobic conditions, respectively. (The ligand L(1)O represents the oxygen insertion product of L(1).) Cryptates 1, 2 and their hydrogenated ligand H(12)(L(1)O) 3 and H(12)L(1) 4 (obtained by reduction of the cryptates) were investigated by electrospray mass spectroscopy (ES-MS). 1 and 2 were also decomposed by HCl treatment and their products were separated and identified by HPLC and ES-MS. Our experiments show that cryptate 2 is able to activate dioxygen that results in quantitative aliphatic hydroxylation of L(1) on one of its HC=N bonds. Crystal structure analysis shows an interesting difference between 1 and 2 in that 1 is an oxygenated and 2 is a non-oxygenated cryptate. Up to date, ligand hydroxylation has not been achieved in silver(I) complex-O(2) systems.

Journal Article↗
PubMed2003

The silica-like extended polymorphism of cobalt(II) imidazolate three-dimensional frameworks: X-ray single-crystal structures and magnetic properties.

Five polymorphous frameworks of cobalt(II) imidazolates (1-5) have been prepared by solvatothermal syntheses. Of these, compound 3 has already been synthesized in a gas-phase reaction by Seel et al. in 1969 and structurally characterized by Sturm et al. in 1975. The new synthetic strategy affords four polymorphous frameworks of cobalt(II) imidazolates (1, 2, 4, 5) of crystalline substances, of which the compound 4 (a = b = 23.450(3), c = 12.460(3) A, tetragonal, I4(1)cd, Z = 16) is an isomorphous compound of [Zn(im)(2)]( infinity ), which was also synthesized in a gas-phase reaction in 1980. The frameworks of compounds 1 and 2 are porous and isostructural; they have the same framework topology that represents a novel uninodal (6,4)-net: 1: a = 18.513(4), b = 24.368(5), c = 9.2940(19) A, orthorhombic, Fdd2, Z = 16; 2: a = 17.635(4), b = 27.706(6), c = 9.0810(18) A, orthorhombic, Fdd2, Z = 16. The framework of compound 5 exhibits a topology of zeolitic structure with the unit-cell parameters: a = 24.3406(8), b = 9.4526(3), c = 24.8470(8) A, beta = 91.977(1) degrees, monoclinic, P2(1)/n, Z = 4. All polymorphous frameworks of cobalt(II) imidazolates reflect the structural features of silica (SiO(2)) and also exhibit different magnetic behaviors, although the imidazolates transmit the antiferromagnetic coupling between the cobalt(II) ions in all cases. However, the uncompensated antiferromagnetic couplings arise from spin-canting are sensitive to the structures: compound 1 is an antiferromagnet with T(N) = 13.11 K; compounds 2-4 are weak ferromagnets (canted antiferromagnets): 2 shows a very weak ferromagnetism below 15 K, 3 exhibits a relatively strong ferromagnetism below 11.5 K and a coercive field (H(C)) of 1800 Oe at 1.8 K, and 4 displays the strongest ferromagnetism of the three cobalt imidazolates and demonstrates a T(C) of 15.5 K with a coercive field, H(C), of 7300 Oe at 1.8 K. However, compound 5 seems to be a hidden canted antiferromagnet with a magnetic ordering temperature of 10.6 K.

Journal Article↗
PubMed1999

Template-Directed One- and Two-Dimensional Copper(II) Diphosphonates: Structures and Characterizations of (NH(4))(2)Cu(3)(hedp)(2)(H(2)O)(4), [NH(3)(CH(2))(4)NH(3)]Cu(3)(hedp)(2).2H(2)O, and [NH(2)(C(2)H(4))(2)NH(2)]Cu(3)(hedp)(2) (hedp = 1-Hydroxyethylidenediphosphonate).

Three new copper(II) diphosphonates, (NH(4))(2)Cu(3)(hedp)(2)(H(2)O)(4) (1), [NH(3)(CH(2))(4)NH(3)]Cu(3)(hedp)(2).2H(2)O (2), and [NH(2)(C(2)H(4))(2)NH(2)]Cu(3)(hedp)(2) (3), where hedp = 1-hydroxyethylidenediphosphonate, have been synthesized and characterized by single-crystal structural analysis. Crystal data: 1, monoclinic, P2(1)/n, a = 6.2137(13) Å, b = 14.747(2) Å, c = 11.1802(12) Å, beta = 105.83(2) degrees, Z = 2; 2, triclinic, P&onemacr;, a = 7.4840(12) Å, b = 8.032(3) Å, c = 10.007(2) Å, alpha = 111.68(2) degrees, beta = 96.188(14) degrees, gamma = 96.97(2) degrees, Z = 1; 3, triclinic, P&onemacr;, a = 7.0155(6) Å, b = 8.0904(9) Å, c = 9.2644(11) Å, alpha = 112.611(13) degrees, beta = 90.819(8) degrees, gamma = 92.824(7) degrees, Z = 1. The compound 1 is composed of infinite chains with a ladder-type motif. The compounds 2 and 3 adopt a two-dimensional layer structure which contains four- and eight-membered rings assembled from vertex-sharing {CuO(4)} units and {CPO(3)} tetrahedra. The magnetic properties of 3 have been investigated.

Journal Article↗
PubMed1999

Design, Synthesis, and Crystal Structure of a cis-Configuration N(2)S(2)-Coordinated Palladium(II) Complex: Role of the Intra- and Intermolecular Aromatic-Ring Stacking Interaction.

A cis-configuration bis(4,5-diazafluorene-9-one thiosemicarbazone) palladium trihydrate, which exhibits approximately five times SHG (second harmonic generation) efficiency of urea, has been designed, synthesized, and structurally characterized. The complex, C(24)H(16)N(10)PdS(2).3H(2)O, crystallizes in trigonal space group P3(1) with cell parameters a = 10.749(2) Å, c = 19.872(4) Å, V = 1988.3(6) Å(3), and Z = 3. The coordination geometry about the Pd(II) is surprisingly a cis-configuration square-planar formed by two imino nitrogen atoms N(3) and N(8) and two sulfur atoms S(1) and S(2) from two thiosemicarbazone ligands. Intramolecular contact analyses in the crystals and 1D and 2D (1)H NMR spectra in solution show that the cis-positioning of the two ligands was stabilized by the pi-pi interaction between the two delocalized diazafluorene moieties. Detailed crystal structure analyses demonstrate that both the intermolecular pi-pi stacking between the diazafluorene planes in different molecules and intermolecular hydrogen bonds between the water molecules and the deprotonated ligands might be the factors that influence the molecules to be packed in the acentric space group P3(1). The crystal structure of the free ligand was also reported here for comparison. The ligand, C(12)H(9)N(5)S, crystallizes in orthorhombic space group Pbca with cell parameters a = 8.432(2) Å, b = 15.427(3) Å, c = 17.387(3) Å, V = 2272.7(8) Å(3), and Z= 8. The thiosemaicarbazone moiety adopts an E configuration with N(1) cis to N(3).

Journal Article↗