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ABSTRACT: A series of 3D homochiral manganese-lanthanide frameworks have been synthesized based on chiral camphoric acid. In the heterometallic features, d-camphoric acids are unprecedentedly embedded in three coordination modes.
Chemical Communications 02/2013; · 6.17 Impact Factor
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ABSTRACT: Up to now, bismuth(III) complexes with thiosemicarbazones have been comparatively rare. Few in vivo biological studies have been carried out in comparison to the plentiful in vitro data. Here, an interesting nine-coordinated bismuth(III) complex, [Bi(H(2)L)(NO(3))(2)]NO(3) [1; H(2)L = 2,6-diacetylpyridine bis((4)N-methylthiosemicarbazone)], has been synthesized and structurally characterized. The analytical data reveal the formation of 1:1 (metal/ligand) stoichiometry. In vitro biological studies have indicated that the bismuth complex 1 has shown much higher antibacterial and anticancer activities than its parent ligand, especially with MIC = 10.66 μM against Bacillus cereus and Salmonella typhimurium and IC(50) = 26.8 μM against K562 leukemia cells, respectively. More importantly, it also evidently inhibits H22 xenograft tumor growth on tumor-bearing mice (10 mg/kg; inhibitory rate = 61.6%). These results indicate that coordination to bismuth(III) might be an interesting strategy in the discovery of new anticancer drug candidates.
Inorganic Chemistry 11/2012; · 4.60 Impact Factor
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ABSTRACT: A 2D Wells-Dawson-based silver(i) coordination polymer was achieved based on silver-Schiff base building blocks and [P(2)Mo(18)O(62)](6-) clusters using AgNO(3), N,N'-bis(furan-2-ylmethylene)hydrazine and Keggin [PMo(12)O(40)](3-) as original materials at room temperature. It is structurally characterized by IR spectroscopy, (31)P NMR, XRPD, thermogravimetric (TG) analyses and X-ray crystallography. The structure of exhibits a novel crystalline 2D coordination polymer constructed by the coordination interaction between the Wells-Dawson polyoxoanion [P(2)Mo(18)O(62)](6-) and Ag-L species. The luminescent property of in the solid state is investigated.
Dalton Transactions 10/2012; · 3.84 Impact Factor
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ABSTRACT: Two metal complexes formulated as [Zn(L)(2)](2)·H(2)O (1) and [Bi(L)(NO(3))(2)(CH(3)OH)] (2), where HL=2-acetylpyrazine N(4)-phenylthiosemicarbazone, have been synthesized and characterized by elemental analysis, IR, MS, NMR and single-crystal X-ray diffraction studies. Biological studies, carried out in vitro against selected bacteria and the K562 leukemia cell lines, respectively, have shown that the free ligand and its two complexes may be endowed with important biological properties, especially HL with MIC=3.90 μg/mL against Pseudomonas aeruginosa, the zinc(II) complex 1 with IC(50)=1.0 μM against K562 leukemia cell lines, respectively. The compounds HL and 1 may exert their cytotoxicity activity via induced loss of mitochondria membrane potential (MMP).
Bioorganic & medicinal chemistry letters 02/2012; 22(7):2418-23. · 2.65 Impact Factor
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ABSTRACT: Two NNS tridentate Schiff base ligands of 2-benzoylpyridine S-methyldithiocarbazate (HL(1)) and 2-benzoylpyridine S-phenyldithiocarbazate (HL(2)) and their transition metal complexes [Cu(2)(L(1))(2)(CH(3)COO)](ClO(4)) (1), [Zn(2)(L(1))(2)(ClO(4))(2)] (2), [Zn(L(2))(2)](3) have been prepared and characterized by elemental analysis, IR, MS, NMR and single-crystal X-ray diffraction studies. In the solid state, each of two Schiff bases remains in its thione tautomeric form with the thione sulfur atom trans to the azomethine nitrogen atom. Under similar prepared conditions, three new complexes showed distinctly different coordination modes depending on their coordinating preferences. Each copper atom in S-bridged dinuclear complex [Cu(2)(L(1))(2)(CH(3)COO)](ClO(4)) (1) is surrounded by five donor atoms in a square-pyramidal fashion (4+1). [Zn(2)(L(1))(2)(ClO(4))(2)] (2) is a dimer in which each zinc atom adopts a seven-coordinate distorted pentagonal bipyramidal geometry, while mononuclear [Zn(L(2))(2)] (3) has octahedral coordination geometry. Biological studies, carried out in vitro against selected bacteria, fungi, and K562 leukaemia cell line, respectively, have shown that different substituted groups attached at the dithiocarbazate moieties and metals showed distinctive differences in the biological property. Zinc(II) complexes 2 and 3 could distinguish K562 leukaemia cell line from normal hepatocyte QSG7701 cell line. Effect of the title compounds on Mitochondria membrane potential (MMP) and PI-associated fluorescence intensity in K562 leukaemia cell line are also studied. The title compounds may exert their cytotoxicity activity via induced loss of MMP.
Journal of inorganic biochemistry 10/2011; 106(1):117-25. · 3.25 Impact Factor
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ABSTRACT: A new inorganic-organic hybrid compound [FTMA](2)[Co(NCS)(4)] (FTMA = ferrocenylmethyltrimethylammonium cation) has been synthesized and characterized by IR, UV, elemental analysis and X-ray crystallography. Co(II) atom has a distorted tetrahedral environment with four N atoms of four NCS(-) anions. In the solid state there are C-H⋯π interactions between adjacent ferrocenyl cations, which generate one-dimensional (1-D) supramolecular chain, and C-H⋯S hydrogen bonds between [FTMA](+) cations and cobalt thiocyanate anions. The title compound shows strong purple fluorescence emission in the solid state at room temperature.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 08/2011; 79(3):570-3. · 2.10 Impact Factor
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ABSTRACT: The polyoxometalate-based 1D coordination polymer [[Cu(DMF)₆][PMo(V)Mo(VI)₁₁O₄₀Cu(DMF)₄]·DMF1 was synthesized and characterized by IR, UV spectroscopy and single-crystal X-ray diffraction analysis. Each Cu(II) center has a distorted octahedral coordination geometry. Cu(1) center interconnects with two [PMo(V)Mo(VI)₁₁O₄₀]⁴⁻ anion subunits and each [PMo(V)Mo(VI)(11)O(40)]⁴⁻ polyoxoanion acts as a didentate ligand to link two Cu centers through two terminal oxygen atoms to form a one-dimensional chain structure. The luminescent properties of 1 in the solution and in the solid state were investigated, respectively.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 11/2010; 77(4):727-31. · 2.10 Impact Factor
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ABSTRACT: A new inorganic-organic hybrid compound [O2NBzQL]4[Cd(SCN)4(NCS)2] (O2NBzQL=1-(4'-NO2-benzyl)quinolinium cation) has been synthesized and characterized by IR, UV, elemental analysis and X-ray crystallography. Cd(II) atom has an distorted octahedral environment with an N4S2 donor set. In solid state there are three types of face-to-face π-π interactions between adjacent cations and multiform C-H⋯S and C-H⋯N hydrogen bonds between [O2NBzQL]+ cations and cadmium thiocyanate anions. The luminescent properties of the title compound were both investigated in H2O solution and in solid state at room temperature, respectively.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 10/2010; 78(1):70-3. · 2.10 Impact Factor
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ABSTRACT: Transition metal complexes Mn(L(1))(2) (1), Mn(L(2))(2) (2), Co(L(3))(2)Cl 4H(2)O (3), Zn(L(3))(2) DMF (4), Co(HL(4))(2)(ClO(4))(2) 3H(2)O (5) and Zn(L(5))(2) DMF (6) where HL(1)=2-acetylpyridine thiosemicarbazone, HL(2)=2-acetylpyridine N(4)-methylthiosemicarbazone, HL(3)=2-benzoylpyridine thiosemicarbazone, HL(4)=2-benzoylpyridine N(4)-methylthiosemicarbazone and HL(5)=2-benzoylpyridine N(4)-phenylthiosemicarbazone, have been synthesized. The complexes 1, 2, 5 and 6 were characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction studies. Preliminary in vitro screening indicated that all the tested compounds showed significant antitumor activity against K562 leucocythemia cancer cell line.
European journal of medicinal chemistry 07/2010; 45(7):3169-77. · 3.27 Impact Factor
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Chemistry 05/2010; 16(24):7082-6. · 5.93 Impact Factor
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ABSTRACT: A series of thiosemicarbazone ligands, HL(1) (2-acetylpyrazine thiosemicarbazone), HL(2) (2-acetylpyrazine N(4)-methylthiosemicarbazone), HL(3) (2-benzoylpyridine thiosemicarbazone) and HL(4) (2-benzoylpyridine N(4)-methylthiosemicarbazone), have been synthesized. The crystal structure of HL(1) has been determined by single-crystal X-ray diffraction. Hydrogen bonds link the different components to stabilize the crystal structure. The antitumor activity of the four ligands were tested against K562 leucocythemia and BEL7402 liver cancer cell lines. All the thiosemicarbazones showed significant antitumor activity. Different substituents on the ligands show different levels of antitumor activity. By comparison with the other thiosemicarbazone species studied, HL(4) with substitution at N(4) position in thiosemicarbazone along with 2-benzoylpyridine is the most active thiosemicarbazone ligand with IC(50)=0.002microm in the K562 leucocythemia cell line and 0.138microm in the BEL7402 liver cancer cell line, respectively.
Bioorganic & medicinal chemistry letters 04/2009; 19(10):2704-6. · 2.65 Impact Factor
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ABSTRACT: Rational self-assembly of Sb(2)O(3) and Na(2)WO(4), or (NH(4))(18)[NaSb(9)W(21)O(86)] with transition-metal ions (Mn(2+), Cu(2+), Co(2+)), in aqueous solution under controlled conditions yield a series of sandwich type complexes, namely, Na(2)H(2)[Mn(2.5)W(1.5)(H(2)O)(8)(B-beta-SbW(9)O(33))(2)]32 H(2)O (1), Na(4)H(7)[Na(3)(H(2)O)(6)Mn(3)(mu-OAc)(2)(B-alpha-SbW(9)O(33))(2)]20 H(2)O (OAc=acetate anion) (2), NaH(8)[Na(2)Cu(4)Cl(B-alpha-SbW(9)O(33))(2)]21 H(2)O (3), Na(8)K[Na(2)K(H(2)O)(2){Co(H(2)O)}(3)(B-alpha-SbW(9)O(33))(2)] 10 H(2)O (4), and Na(5)H[{Co(H(2)O)(2)}(3)W(H(2)O)(2)(B-beta-SbW(9)O(33))(2)]11.5 H(2)O (5). These structures are determined by using the X-ray diffraction technique and further characterized by obtaining IR spectra and performing elemental analysis. Structure analysis reveals that polyoxoanions in 1 and 5 comprise of two [B-beta-SbW(9)O(33)](9-) building units, whereas 2, 3, and 4 consist of two isomerous [B-alpha-SbW(9)O(33)](9-) building blocks, which are all linked by different transition-metal ions (Mn(2+), Cu(2+), or Co(2+)) with different quantitative nuclearity. It should be noted that compound 2 represents the first one-dimensional sinusoidal chain based on sandwich like tungstoantimonate building blocks through the carboxylate-bridging ligands. Additionally, 3 is constructed from sandwiched anions [Na(2)Cu(4)Cl(B-alpha-SbW(9)O(33))(2)](9-) linked to each other to form an infinitely extended 2D network, whereas 5 shows an interesting 3D framework built up from offset sandwich type polyoxoanion [{Co(H(2)O)(2)}(3)W(H(2)O)(2)(B-beta-SbW(9)O(33))(2)](6-) linked by Co(2+) and Na(+) ions. EPR studies performed at 110 K and room temperature reveal that the metal cations (Mn(2+), Cu(2+), Co(2+)) reside in a square-pyramidal geometry in 2, 3, and 4. The magnetic behavior of 1-4 suggests the presence of weak antiferromagnetic coupling interactions between magnetic metal centers with the exchange integral J=-0.552 cm(-1) in 2.
Chemistry - An Asian Journal 06/2008; 3(5):822-33. · 4.50 Impact Factor
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ABSTRACT: A new organic–inorganic polyoxometalate compound [Co(2,2′-bipy)3]H[Al(OH)6 (Mo6O18)] · 17H2O has been synthesized and characterized by elemental analysis, IR, UV spectra, thermogravimetry and differential thermal analysis (TG-DTA) and single-crystal X-ray diffraction analysis. The title compound crystallizes in a monoclinic, C2/c space group, with a = 37.292(8), b = 14.214(3), c = 25.050(5) Å, β = 120.62(3), V = 11426(4) Å3, Z = 8, F(000) = 7200, D c = 2.116 Mg m−3, R = 0.0748, wR 2 = 0.1853. Crystal structural analysis indicates that the asymmetric unit in the crystal structure of the title compound consists of one B-Anderson–Evans type heteropolyoxoanion, one octahedral [Co(2,2′-bipy)3]2+ coordination cation, seventeen water molecules of crystallization and a proton based on charge balance. The curves of TG-DTA indicate that weight loss of the title compound is divided into three stages. The third weight loss reveals that the backbone of heteropolyoxoanion decomposes at 744°C.
Journal of Coordination Chemistry. 06/2007; 60(12):1327-1334.
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ABSTRACT: Five novel polyoxometalate compounds built on the lacunary Keggin-type polyanion [GeW11O39]8- and trivalent rare earth ions (M = Nd, Sm, Y, Yb), [(CH3)4N]2H1.50[Nd1.50(GeW11O39)(H2O)6]·3H2O (1), [(CH3)4N]2H2.25[Sm1.25(GeW11O39) (H2O)4]·3.75H2O (2), [(CH3)4N]2.50H2.50[Y(GeW11O39)(H2O)2]·4H2O (3), [(CH3)4N]2.50H2.50Yb(GeW11O39)(H2O)2]·3.75H2O (4), and [Sm(H2O)7]0.5H0.5[Sm2(GeW11O39)(DMSO)3(H2O)6]·3.5H2O (5) (DMSO = dimethyl sulfoxide) have been synthesized and characterized by elemental analysis, IR and UV spectroscopy, and single-crystal X-ray diffraction. The solid-state structures of compounds 1 and 2 consist of one-dimensional zigzag chains built of [α-GeW11O39]8- anions connected by Nd3+/Sm3+ cations, while the linkage of the building blocks by Y3+/Yb3+ centers in 3 and 4 leads to the formation of linear wires. Compound 5 displays a double-parallel chainlike structure constructed by two linear wires linked by samarium coordination cations.
09/2006;
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ABSTRACT: Three novel organic−inorganic hybrid monovacant Keggin-type silicotungstates and germanotungstates containing lanthanideIII cations with 1D and 2D infinitely extended structures, [Sm(H2O)6]0.25[Sm(H2O)5]0.25H0.5{Sm(H2O)7[Sm(H2O)2(DMSO)(α-SiW11O39)]}·4.5H2O (DMSO = dimethyl sulfoxide) (1), [Dy(H2O)4]0.25[Dy(H2O)6]0.25H0.5{Dy(H2O)7[Dy(H2O)2(DMSO)(α-GeW11O39)]}·5.25H2O (2), and H{[Sm(H2O)5.5(DMF)0.5]2[Sm(H2O)2(DMF)][Sm(H2O)3(α-SiW11O39)]2} (DMF = N,N-dimethyl formamide) (3), have been synthesized in aqueous solution under moderate conditions and further characterized by elemental analyses, inductively coupled plasma (ICP) analyses, IR, UV spectra, and X-ray diffraction. Compounds 1 and 2 reveal the one-dimensional chain infinitely extended structure, while compound 3 represents the first example of a two-dimensional network structure formed by the monovacant Keggin-type [α-SiW11O39]8- chain through the linkage of rare earth metal−organic coordination cations. From thermogravimetric (TG/DTA) analyses, the polyanion frameworks of 1 and 2 retain a comparatively good thermal stability. Variable temperature magnetic susceptibility indicates that compounds 1 and 3 obey the Curie−Weiss law in the higher temperature region from 130 to 300 K, while in the lower temperature region from 2 to 130 K they show the occurrence of strong spin−orbital coupling interactions and very weak ferromagnetic responses.
01/2006;
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ABSTRACT: A new composite complex of the general formula [Yb(DMSO)7]H[SiMo12O40] has been synthesized from H4SiMo12O40⋅nH2O, YbCl3 and DMSO in mixed solvent of acetonitrile and water and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. Singe crystal X-ray structure analysis shows that it belongs to monoclinic system, space group P21/c, with a = 11.685(2) , b = 14.969(3) , c = 35.037(7) , β = 98.50(3)∘, and Z = 4. There is one [Yb(DMSO)7]3+ coordinated cation and one [SiMo12O40]4− polyanion in one structure unit. The organic ligands (DMSO) do coordinate directly with ytterbium(III) to form a distorted pentagonal bipyramid complex ion by coordination bond, then combines to the SiMo12O404− anion by static electric force. The results of IR and X-ray diffraction show that there is strong interaction between polyoxometalate and organic donors.
Journal of Chemical Crystallography 12/2004; 35(8):629-634. · 0.57 Impact Factor
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ABSTRACT: Two composite compounds, [{Ce(DMF)4(H2O)3}{Ce(DMF)4(H2O)4}(P2W18O62)]·H2O (1) (DMF = N,N-dimethylformamide) and [{La(DMF)6(H2O)}{La(DMF)4.5(H2O)2.5}·(P2W18O62)] (2), have been constructed at room temperature and characterized by single crystal X-ray structural analyses, ESR spectroscopy, and thermogravimetric (TG) and differential thermal analysis (DTA) measurements. Single crystal X-ray structural analyses reveal that the adjacent polyanions are polymerized to form a 1D infinitely linear chain by the bridging RE coordination cations and exhibit an -ACACAC- type of structure, and that two types of terminal oxygen atoms of the Wells−Dawson polyanion located in the “cap” and “belt” sites are involved in coordination with the RE3+ ions, respectively. ESR spectra indicate that after irradiation with sunlight, compound 2 forms a mixed-valence heteropoly compound with unshared electrons. From TG-DTA analyses, we surmise that the frameworks of polyanions of this kind of compound decompose at ca. 620 °C.
01/2004;
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ABSTRACT: The structures of three 1:1 composite compounds prepared with the polyoxometalate (POM) [PMo12O40]3− and the cations [Ln(NMP)6]3+ [Ln = La (1), Ce (3), Pr (2); NMP = N-methyl-2-pyrrolidone] exhibit two types of zig-zag chains with alternating cations and anions through Mo−Ot−Ln−Ot−Mo links in the crystal. The compounds were characterized by IR, UV, and ESR spectroscopy, single-crystal X-ray structural analysis, and by a study of their thermal properties. In all the compounds, the La3+, Pr3+, and Ce3+ centers are eight-coordinate with the oxygen atoms in bicapped trigonal-prismatic geometries. The variation of the average Ln−O separations along the La, Ce, and Pr series is consistent with the effects of the lanthanide contraction. The results of the single-crystal X-ray diffraction analyses and the IR spectroscopic studies are in agreement and both show the metal cation units are coordinatively bonded to the Keggin clusters. The UV spectra of the title compounds suggest that their structures are entirely disrupted in dilute solution. Low-temperature ESR spectra indicate that thermal electron delocalization occurs among the Mo atoms in the three compounds. The results of cyclic voltammetry (CV) show that compounds 1, 2, and 3 all undergo five two-electron reversible reductions and that the [PMo12O40]3− anions are the active centers for electrochemical redox reactions in solution, while the corresponding cations have only a small effect on the electrochemical properties. Studies of magnetic properties show that 1 is diamagnetic, while 2and 3 exhibit antiferromagnetic Pr−Pr or Ce−Ce exchange interactions. In addition to the results of CV, the average bond lengths and the magnetic properties of compound 3 indicate that the oxidation state of cerium is III in the compound of formula [{Ce(NMP)6}(PMo12O40)]n. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Berichte der deutschen chemischen Gesellschaft 10/2003; 2004(1):160 - 170. · 2.94 Impact Factor
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Journal of Coordination Chemistry. 04/2003; 56(6):523-530.
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ABSTRACT: Self-assembly of the building block [Cu(oxbe)](-) with Mn(II) led to a novel coordination polymer ([Cu(oxbe)]Mn(H(2)O)[Cu(oxbe)(DMF)])n).nDMF.nH(2)O, where H(3)oxbe is a new dissymmetrical ligand N-benzoato-N'-(2-aminoethyl)oxamido and DMF = dimethylformamide. The crystal forms in the triclinic system, space group Ponemacr;, with a = 9.260(4) A, b = 12.833(5) A, c = 15.274(6) A, alpha = 76.18(3) degrees, beta = 82.7(3) degrees, gamma = 82.31(3) degrees, and Z = 2. The crystal structure of the title complex reveals that the two-dimensional bimetallic layers are constructed of Cu(II)Mn(II)Cu(II) chains linked together by carboxylate bridge and hydrogen bonds help to produce a novel three-dimensional channel-like structure. The magnetic susceptibility measurements (5-300 K) were analyzed by means of the Hamiltonian H = -2JS(Mn)(S(Cu1) + S(Cu2)), leading to J = -17.4 cm(-1).
Inorganic Chemistry 03/2003; 42(3):761-6. · 4.60 Impact Factor
