39,983 Works

Two 3-D metal organic frameworks containing 2,2′-bipyridine-5,5′-dicarboxylic acid: synthesis, structure, and magnetic properties

Ming Fang, Tao Wang, Xulin Lu, Aijun Song, Li Shen & Hongyan Tian
Two metal organic frameworks, {[M(H2BPDC)(SO4)]}n (M = Mn (1), Zn (2)); BPDC = 2,2′-bipyridine-5,5′-dicarboxylic anion), have been synthesized under hydrothermal conditions. The structure analyses of 1 and 2 reveal that the two compounds have similar 3-D structures. Compound 1 crystallizes in the orthorhombic system with space group Pnma, while 2 displays a monoclinic system with space group P21/n. Magnetic investigation suggests that weak antiferromagnetic coupling exists between adjacent Mn2+ ions in 1. Two metal organic...

A 2-D organic–inorganic supramolecular layer based on a {P2Mo5} cluster bridged by Mn(II) and pentanuclear fragment linker

Jie Shi, Chunxiao Wang, Kai Yu, Zhanhua Su, Chunmei Wang & Baibin Zhou
An organic–inorganic hybrid based on {P2Mo5} clusters, (H2bim)3[{Na0.5(H2O)0.5}2{Mn(OH)4(H2O)2}{Na0.5(H2bim)}2{Mn(H2O)4(P2Mo5O23)2}]·4H2O (1) (bim = 2,2′-biimidazole), was hydrothermally synthesized and characterized by elemental analyses, IR, TG, UV, and single crystal X-ray diffraction analyses. In 1, four Na ions, one Mn, and two bim ligands are linked by four μ–O bridges to form unusual pentanuclear fragments [{Na0.5(H2O)0.5}2{Mn(OH)4(H2O)2}{Na0.5(H2bim)}2]. Each pentanuclear segment links adjacent to four Standberg units to form supramolecular dimer chains, which are further connected by Mn(H2O)4 linkers to yield...

Three Cu(II) (R)-2-chloromandelato complexes generated from dipyridyl-type ligands with different spacer lengths: syntheses, crystal structures, and ferroelectric properties

Jin-Li Qi, Sheng-Liang Ni, Wei Xu & Yue-Qing Zheng
Three Cu(II) complexes, Cu2(bpy)(H2O)(Clma)2 (1), Cu2(bpe)(H2O)2(Clma)2 (2), and Cu(bpp)(Clma) (3), were synthesized (HClma = (R)-2-Chloromandelic acid, bpy = 4,4′-dipyridine, bpe = 1,2-di(4-pyridyl)ethylene, bpp = 1,3-di(4-pyridyl)propane). Complexes 1, 2, and 3 are constructed from 1-D coordination arrays generated from Cu2(H2O)(Clma)2, Cu2(H2O)2(Clma)2, and Cu2(Clma)2 moieties and linked through bpy, bpe, and bpp co-ligands, respectively. 1 and 2 are assembled into 3-D supramolecular networks via O–H⋯O hydrogen bonds with topology of (63)(69·8) and (412·63), respectively, and 3 is...

Synthesis, structural characterization, and photocatalytic study of transition metal coordination polymers constructed from mixed ligands

Xiao-Guang Sang & Xiao-Xia Liu
Three 3-D coordination polymers, [Cu(cca)(4,4′-bipy)]n (1), [Co3(pda)3(1,10′-phen)2]n (2), and [Co(pda)(1,10′-phen)]n (3), have been synthesized from 4-carboxycinnamic acid (cca), 1,4′-phenylenediacrylic acid (pda), 4,4′-bipyridine (4,4′-bipy), 1,10′-phenanthroline (1,10′-phen), and Cu and Co salts under different conditions. The X-ray crystal structures of these three complexes are presented. Complex 1 exhibits a threefold 3-D α-Po interpenetration network. Complex 2 with a 3-D framework with six-connected single α-Po framework constructed from Co3 unit has been synthesized and characterized. Complex 3 shows...

Dissociation kinetics of macrocyclic trivalent lanthanide complexes of 1-oxa-4,7,10-triazacyclododecane-4,10-diacetic acid (H2ODO2A)

C. Allen Chang, Chih-Cheng Lin & Chien-Hung Kuo
The dissociation kinetics of selected trivalent lanthanide (Ln3+, Ln=La, Pr, Eu, Er, Lu) complexes of the macrocyclic ligand H2ODO2A (1-oxa-4,7,10-triazacyclododecane-4,10-diacetic acid), LnODO2A+, were studied in the [H+] range (0.1–2.4) × 10−4 M in the temperature range 15–45 °C. Excess Cu2+ ions were used as the scavenger for the ligand in acetate–acetic acid buffer medium. The dissociation reactions are independent of [Cu2+] and follow the rate law kobs = kd + kAC[Acetate] + K′klim[H+]/(1 + K′[H+]),...

Syntheses, crystal structures, and electrochemical studies of Fe2(CO)6(μ-PPh2)(μ-L) (L = OH, OPPh2, PPh2)

Yao-Cheng Shi, Wei Yang, Ying Shi & Da-Cong Cheng
Reaction of Fe3(CO)12 and Ph2PH in the presence of Et3N in THF at 0 °C immediately forms Fe2(CO)6(μ-PPh2)(μ-OH) (1), Fe2(CO)6(μ-PPh2)(μ-k2O,P-OPPh2) (2), and Fe2(CO)6(μ-PPh2)2 (3) in yields of 25, 14, and 19%, respectively. Experiments confirm that Et3N shortens the reaction time. The absence of O2 hinders the formation of 2. The presence of H2O can increase the yield of 1. Their structures have been determined by X-ray crystallography and the complexes have been completely characterized by...

Structure and magnetism of a new 2-D trinuclear Mn(II) polymer

Lu Lu, Fu-Min Wang, Jun Wang, Bin Xie & Jian-Qiang Liu
A new complex, {[Mn3(oba)2(IP)2(CH3COO)2]·H2O}n (1) (H2oba = 4,4′-oxybis(benzoic acid), IP = 1-H-imidazo[4,5-f][1,10]-phenanthroline), has been synthesized and structurally characterized by single-crystal diffraction analysis. The structural determination revealed that 1 has a 2-D grid motif, which can be further linked into a 3-D porous network via packing interactions. The magnetic properties of 1 are discussed. A new complex has been synthesized and structurally characterized. The title compound shows 3D porous network via the packing interactions. In addition,...

Cytotoxicity towards human alimentary system carcinoma cells resulting from diverse copper(II) complexes

Jin’an Zhao, Kun Peng, Yan Guo, Jin Zhang, Dandan Zhao, Shufang Chen & Jiyong Hu
To investigate the potential cytotoxicity of copper(II)-based complexes, three coordination compounds with heterocyclic ligands, Cu(pbmbt)Cl2(CH3OH) (1), Cu2(ddbib)2(NO3)4·3CH3OH (2), and Cu3(ttmtmb)2Cl6·2.5H2O (3), which include mononuclear, dinuclear, and trinuclear structures, have been synthesized from reactions of corresponding copper(II) salts with 1-((2-pyrazinyl)-1H-benzoimidazol-1-yl)methyl)-1H-benzotriazole (pbmbt), 2-(2,3-dihydropyrazin-2-yl)-1-((4-((2-(2,3-dihydropyrazin-2-yl)-1H-benzo[d]imidazol-1-yl)methyl)phenyl)methyl)-1H-benzo[d]imidazole (ddbib), and 1,1′,1′′-((2,4,6-trimethylbenzene-1,3,5-triyl)tris(methylene)tris(2-methyl-1H-benzoimidazole) (ttmtmb), respectively. IC50 values revealed that 2 and 3 show strong cytotoxicity, whereas 1 is weakly cytotoxic after being tested against a panel of several human alimentary system carcinoma cell lines...

Plant growth-promoting rhizobacteria reduce adverse effects of salinity and osmotic stress by regulating phytohormones and antioxidants in Cucumis sativus

Sang-Mo Kang, Abdul Latif Khan, Muhammad Waqas, Young-Hyun You, Jin-Ho Kim, Jong-Guk Kim, Muhammad Hamayun & In-Jung Lee
We assessed the role of plant growth-promoting rhizobacteria (PGPR) strains viz. Burkholdera cepacia SE4, Promicromonospora sp. SE188 and Acinetobacter calcoaceticus SE370 in counteracting salinity and drought stress to cucumber plants. The control plants had stunted growth, while PGPR-treated plants had significantly higher biomass and chlorophyll contents under salinity and drought stress. The ameliorative effects of PGPR-application were also evidenced by the increased water potential and decreased electrolytic leakage. The PGPR-applied plants had reduced sodium ion...

Phytotoxicity induced by Phragmites australis: an assessment of phenotypic and physiological parameters involved in germination process and growth of receptor plant

Md N. Uddin, Randall W. Robinson & Domenic Caridi
This study investigated the possible phytotoxicity induced by Phargmites australis on phenotypic and physiological parameters of recipient plants with identification of major inhibitors in the donor plant. This was achieved using aqueous extracts of different organs and root exudates of P. australis in laboratory and greenhouse experiments with Lactuca sativa as the model test plant. The observed reduced liquid imbibition and altered resource mobilization in seeds of L. sativa, in particular an insufficient carbohydrate supply,...

Bioactive chemical constituents produced by endophytes and effects on rice plant growth

Muhammad Waqas, Abdul Latif Khan & In-Jung Lee
We investigated the bioactive potential of fungal endophytes isolated from the roots of Glycine max (L.) Merr. and Cucumis sativus. Initial screening results showed that endophytes, (Chrysosporium pseudomerdarium, Aspergillus fumigates and Paecilomyces sp., Penicillium sp., Phoma glomerata, and Paecilomyces formosus) were promoting the growth attributes (shoot length, chlorophyll contents, and biomass) of mutant and wild-type rice. To know whether, these endophytes were producing bioactive chemical constituents; the endophytes were grown in potato dextrose, czapek broth,...

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