Shao-Song Qian

Syntheses, Crystal Structures, Thermal Stability, and Fluorescence Properties of Zinc(II) Complexes With Tridentate Schiff Bases

Two new mononuclear Schiff base zinc(II) complexes, [Zn (NMP)(MeCOO)] (1) and [ZnBr2(MP)]·MeOH·H2O (2) (NMP = 4-nitro-2-[(3-morpholin-4-ylpropylimino)methyl]phenolate; MP = 2-[(3-morpholin-4-ylpropylimino)methyl]phenolate), have been synthesized from the similar tridentate Schiff base ligands. The complexes were characterized by elemental analysis, infrared spectra, and single-crystal X-ray diffraction. The Zn atom in 1 is five-coordinated in a distorted Squire-pyramidal geometry by the NNO donor set of NMP and two O atoms of an acetate ligand. The Zn atom in 2 is four-coordinated in a tetrahedral geometry by the imino N and phenolate O atoms of MP and two Br atoms. The thermal stability and fluorescence properties of the complexes have also been determined.

Synthesis, crystal structures, and fluorescent properties of zinc and cadmium(II) complexes with tridentate Schiff bases

A new dinuclear zinc(II) complex, [Zn2(L1)2(N3)2] (1), and a new polynuclear cadmium(II) complex, [Cd2(L2)2(NO3)(μ2-dca)]n (2), where L1 and L2 are deprotonated forms of 2-[(2-ethylaminoethylimino)methyl]-6-methylphenol and 2-[(2-ethylaminoethylimino)methyl]-4-methoxyphenol, respectively, have been prepared and characterized by elemental analysis, IR spectra, and single crystal X-ray diffraction. The thermal stability and fluorescence of the complexes were also investigated.

Synthesis and biological evaluation of Cu(II), Zn(II), and Ni(II) 3-(4-nitrophenyl)acrylic acid complexes with diamines as potential urease inhibitors

Five new Cu(II), Zn(II), and Ni(II) 3-(4-nitrophenyl)acrylic acid complexes were synthesized and evaluated for inhibitory activity on jack bean urease. All five complexes were structurally determined by single crystal X-ray analysis. Compared with the positive reference acetohydroxamic acid (IC50 = 13.25 μM), Cu(II) complexes 3 and 4 showed the strongest inhibitory activity against jack bean urease (IC50 = 1.23 and 1.17 μM). Ni(II) and Zn(II) complexes also exhibited inhibitory activities (IC50 = 10.09–13.10 μM).

Synthesis, crystal structures, and magnetic properties of tetranuclear nickel(II) and copper(II) complexes with tridentate Schiff bases

Two cubane-type tetranuclear nickel(II) and copper(II) complexes, [Ni4(L1)4(CH3OH)4] (1) and [Cu4(L2)4]·H2O (2), where L1 and L2 are the dianionic forms of the tridentate Schiff bases 4-nitro-2-[(2-hydroxyethylimino)methyl]phenol (H2L1) and 5-methoxy-2-[(2-hydroxyethylimino)methyl]phenol (H2L2), respectively, have been synthesized and characterized by physicochemical methods and single-crystal X-ray diffraction. The magnetic properties of the complexes show the presence of ferromagnetic interactions for complex 1 and antiferromagnetic interactions for complex 2, mediated by hydroxyl bridges.

Synthesis, characterization, and biological evaluation of silver(I) complexes of N′-(1-(pyrazin-2-yl)ethylidene)picolinohydrazide

Abstract Three Ag+ complexes, [Ag(L)(NO3)]n (1), {[Ag(L)]·SbF6·CH2Cl2}n (2), and {[Ag(L)]·SO3CF3·CHCl3}n (3), based on a hydrazone ligand L have been obtained (L = N′-(1-(pyrazin-2-yl)ethylidene)picolinohydrazide) and characterized. Complexes 1–3 all show 1-D chain-like structures. Their antibacterial activity and interaction with serum albumin were investigated. These results indicate that these complexes show good antibacterial activities and binding affinity to serum albumin.

Discovery of phenylpiperazine derivatives as IGF-1R inhibitor with potent antiproliferative properties in vitro.

A series of phenylpiperazine derivatives (3a-3q) were designed and synthesized. In vitro assays indicated that several phenylpiperazine derivatives had excellent antiproliferative properties against four cancer cell lines including multidrug-resistant cancer cell lines, with IC50 values in the low micromolar range. The average IC50 of the most active compound 3b is 0.024μM to the MCF-7 cell line. In addition, the mechanism of action of these new analogues was investigated by molecular docking studies, insulin-like growth factor 1-receptor (IGF-1R) kinase assay and apoptosis induced assay. These studies confirmed that these new phenylpiperazine derivatives maintain their mechanisms of action by disrupting IGF-1R kinase.

Syntheses and Crystal Structures of Cobalt(III) and Manganese(III) Complexes With bis-Schiff Bases

A new mononuclear Schiff base cobalt(III) complex, [Co(MEA) (N3)(DMF)] (1), and a new mononuclear Schiff base manganese(III) complex, [Mn(EEA)(N3)(OH2)] (2) (MEA is bis (5-methoxysalicylidene)ethylenediamine; EEA is bis(6-ethoxys alicylidene)ethylenediamine), have been prepared and structurally characterized by physicochemical and single-cyrstal X-ray diffraction. Complex 1 crystallizes in the monoclinic space group P21/c with unit cell dimensions a = 9.910(1) Å, b = 19.279(1) Å, c = 12.410(1) Å, β = 102.729(2)°, V = 2312.8(2) Å3, Z = 4, R 1 = 0.0319, and wR 2 = 0.0779. Complex 2 crystallizes in the monoclinic space group P21/c with unit cell dimensions a = 14.252(2) Å, b = 22.227(3) Å, c = 13.613(2) Å, β = 91.512(2)°, V = 4310.7(11) Å3, Z = 8, R 1 = 0.0392, and wR 2 = 0.0839. The metal atom in each complex is in an octahedral coordination. Crystal of complex 2 was stabilized by hydrogen bonds.

Syntheses and crystal structures of copper(II) and nickel(II) complexes derived from 2-bromo-4-chloro-6-[(2-methylaminoethylimino)methyl]phenol

A new centrosymmetric mononuclear copper(II) complex [Cu(L)2](ClO4)2 (I) and a new centrosymmetric mononuclear nickel(II) complex [Ni(L)2(MeOH)2](ClO4)2 (II), where L is the zwitterionic ligand 2-bromo-4-chloro-6-[(2-methylammonioethylimino)methyl]phenolate, have been prepared from the Schiff base 2-bromo-4-chloro-6-[(2-methylaminoethylimino)methyl]phenol with copper perchlorate and nickel perchlorate, respectively. The complexes were characterized by elemental analysis, infrared spectra, and single-cyrstal X-ray diffraction (CIF files CCDC nos. 1408054 (I) and 1407973 (II)). Complex I crystallizes in the monoclinic space group P21/c with unit cell dimensions a = 7.7736(4), b = 21.608(1), c = 8.5194(4) Å, β = 93.907(2)°, V = 1427.7(1) Å3, Z = 2, R1 = 0.0546, and wR2 = 0.1531. Complex II crystallizes in the monoclinic space group P21/c with unit cell dimensions a = 21.324(3), b = 16.821(2), c = 9.425(1) Å, β = 90.114(2)°, V = 3380.5(7) Å3, Z = 4, R1 = 0.0693, and wR2 = 0.1627. The Cu atom in I is in square planar coordination, and the Ni atom in II is in octahedral coordination.

Azido and Thiocyanato-Bridged Polymeric Copper(II) Complexes [CuL(μ1,3-N3)]n·2nH2O and [CuL(μ1,3-NCS)]n: Synthesis and Structures

A new azido-bridged polymeric copper(II) complex, [CuL(μ1,3-N3)]n·2nH2O (1), and a new thiocyanato-bridged polymeric copper(II) complex, [CuL(μ1,3-NCS)]n (2) (L = 4-methoxy-2-[(2-morpholin-4-ylethylimino)methyl]phenolate), have been prepared and structurally characterized by elemental analysis, IR spectra, and single-crystal X-ray determination. Each Cu atom in the complexes is coordinated by three donor atoms of Schiff bases and by two atoms of the pseudohalide ligands, forming a square pyramidal geometry. Azide and thiocyanate anions are preferred bridging groups for the construction of polymeric copper complexes with Schiff bases.

Syntheses, crystal structures, and fluorescence properties of Zinc(II) complexes with multi-dentate Schiff bases

Two new structurally similar mononuclear Schiff base zinc(II) complexes, [ZnBr(ClMP)] (I) and [ZnCl(NMP)] (II) (ClMP = 4-chloro-2-[(3-morpholin-4-ylpropylimino)methyl]phenolate; NMP = 4-nitro-2-[(3-morpholin-4-ylpropylimino)methyl]phenolate), and two new dinuclear Schiff base zinc(II) complexes, [Zn2(EMP)2I2] (III), and [Zn2(MPA)(CH3OH)2(N3)2] (IV) (EMP = 5-diethylamino-2-[(2-dimethylaminoethylimino)methyl]phenolate; MPA = N,N′-bis(3-methoxysalicylidene)propane-1,3-diamine), have been prepared and characterized mainly by single-cyrstal X-ray diffraction. Complex I crystallizes in the monoclinic space group P21/n with unit cell dimensions: a = 15.116(3), b = 9.465(1), c = 23.714(4) Å, β = 104.358(2)°, V = 3286.9(8) Å3, Z = 8, R1 = 0.0439, and wR2 = 0.0736. Complex II crystallizes in the monoclinic space group P21/c with unit cell dimensions: a = 7.253(2), b = 16.652(4), c = 13.568(3) Å, β = 96.600(2)°, V = 1627.8(6) Å3, Z = 4, R1 = 0.0417, and wR2 = 0.0809. Complex III crystallizes in the monoclinic space group C2/c with unit cell dimensions: a = 27.962(2), b = 8.246(2), c = 31.605(3) Å, β = 90.343(2)°, V = 7287.4(15) Å3, Z = 8, R1 = 0.0721, and wR2 = 0.1709. Complex IV crystallizes in the monoclinic space group C2/c with unit cell dimensions: a = 20.483(3), b = 11.344(2), c = 14.909(3) Å, β = 131.650(1)°, V = 2588.6(7) Å3, Z = 4, R1 = 0.0343, and wR2 = 0.0792. Each Zn atom in I and II are four-coordinated in a tetrahedral geometry by the NNO donor set of the Schiff base ligand and one halide atom. The Zn atoms in III are in square pyramidal coordination, and those in IV are in octahedral and tetrahedral coordination. Thermal stability and fluorescence properties of the complexes I and II have also been determined.