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Polyhedron
Pergamon Press
Polyhedron

Pergamon Press

0277-5387

Polyhedron/Journal PolyhedronSCICCREI
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    Luminescent Cu(I) and Au(I) complexes based on diphenyl(5-pyrimidyl) phosphine

    Baranov, Andrey YuRyadun, Alexey A.Sukhikh, Taisiya S.Artem'ev, Alexander, V...
    7页
    查看更多>>摘要:Diphenyl(5-pyrimidyl)phosphine (L) has been synthesized and its coordination abilities toward Cu(I) and Au(I) have been surveyed. The reaction of L with Cu(MeCN)(4)BF4 or CuI produces 1D polymers [Cu(L)(MeCN)(2)]BF4 and [Cu2I2(L)(2)], or 2D grids [Cu2I2(L)(2)], wherein P,N-bridging pattern of the ligand always appears. Treatment of L with 1 or 3 equiv. of Au(tht)Cl affords linear [Au(L)Cl] or trigonal pyramidal [Au(L)(3)Cl] complexes, in which the ligand is P-coordinated to Au(I). At 300 K, 1D polymers [Cu(L)(MeCN)(2)]BF4 and [Cu2I2(L)(2)] exhibit weak yellow and moderate green emission, respectively, which strongly enhances upon colling to 77 K. Complex [Au(L)(3)Cl] at 300 K emits strong sky-blue phosphorescence (lambda(em) = 492 nm) with the quantum yield of 50%.

    Homo- and heterometallic oxalate-based complexes obtained using [Cr (C2O4)(3)](3-) building block - Two polymorphs of a solvate

    Kanizaj, LidijaMolcanov, KresimirDubraja, Lidija AndrosKlaser, Teodoro...
    8页
    查看更多>>摘要:Two heterometallic complex salts, as polymorphs of a solvate, consisting of three different mononuclear units, [CuCl(phen)(2)][Cu(H2O)(phen)(2)][Cr(C2O4)(3)]center dot nH(2)O [n = 5 (1) and n = 8 (2); phen = 1,10-phenanthroline] were obtained in reactions in which [Cr(C2O4)(3)](3-) was used as a building unit. The polymorphs of a solvate are obtained in crystalline forms that differ in type or stoichiometry of included solvent molecules, mostly obtained under different conditions. In this [CuIICrIII] system, the used solvents and crystallization method influence the final product, i.e., the formation of a specific solvatomorph. From the reaction of an aqueous solution of K-3[Cr (C2O4)(3)]center dot 3H(2)O and acetonitrile solutions containing phen and CuCl2 center dot 2H(2)O, compound 1 was formed when the layering technique is used; and compound 2 can be obtained from the mixture of these reactants, but using methanol instead of acetonitrile. Based on the index parameter for the degree of trigonality, tau, the geometry of copper(II) atoms of the [Cu(H2O)(phen)(2)](2+) cations in 1 and 2 are distorted from square pyramidal toward trigonal bipyramidal conformation, while those of [CuCl(phen)(2)](+) have a trigonal bipyramidal geometry. Interestingly, in the presence of [NBu4](+) cations, and applying slow liquid diffusion, partial decomposition of the building block [Cr(C2O4)(3)](3-) occurred and the homobinuclear oxalate-bridged complex [{Cu(bpy)Cl}(2)(mu-C2O4)]center dot CH3OH (3; bpy = 2,2'-bipyridine) was formed. Consequently, the oxalate ligand released from the coordination sphere of Cr-III was coordinated to Cu-II ions during the crystallization process. The obtained oxalate-based compounds 1-3 were characterized by IR spectroscopy and single-crystal X-ray diffraction.

    Bis(phenyl-beta-diketonato)titanium(IV) ethoxide complexes: Ring-opening polymerization of L-lactide by solvent-free microwave irradiation

    Janeway, Felix D.Bird, LauraMcGowan, Patrick C.Lord, Rianne M....
    8页
    查看更多>>摘要:A range of functionalized bis(phenyl-beta-diketonato)titanium(IV) ethoxide complexes of the type [Ti(L)(2)(OEt)(2)], containing two asymmetric or symmetric phenyl-beta-diketonate ligands (L), have been synthesized and fully characterized. Single crystal X-ray diffraction has been used to confirm that all structures crystallize with the ethoxide ancillary ligands in a cis arrangement and NMR spectra show characteristic ligand rearrangement in solution. The complexes have been screened as catalysts in the ring-opening polymerization (ROP) of L-lactide (LLA) to yield polylactide (PLA), by using microwave (MW) and conventional heating. The resulting polymers have high molecular weights but high polydispersity index (PDI) which are suggestive of transesterification. However, unlike conventional heating methods, the polymerization by MW reaction leads to a retention in stereochemistry of the resulting polymer in significantly shorter time periods.

    Cadmium(II) coordination polymer based on flexible dithiolate-polyamine binary ligands system: Crystal structure, Hirshfeld surface analysis, antimicrobial, and DNA cleavage potential

    Bhattacharjee, TirthaAdhikari, SumanDatta, AbhijitDaniliuc, Constantin-Gabriel...
    9页
    查看更多>>摘要:The mononuclear chelating complex [Cd(i-mnt)(tren)]n (1) fabricated from binary ligand systems 1,1-dicyano-ethylene-2,2-dithiolate (i-mnt2) and diethylenetriamine (tren) has been synthesized and structurally charac-terized by spectroscopic methods (IR, NMR). The single-crystal X-ray diffraction study reveals that Cd+2 has CdN3S3 coordination kernel having distorted trigonal prism geometry (TP) [twist angle (theta) 37.6(11)0] and the secondary ligand tren influences the ligation pattern of i-mnt2 towards metal center in the formation of 1D polymeric chain where asymmetric units linked by bridging thiolate S2-atom of each i-mnt2. The N - H...N, N - H...S type hydrogen bonds link the 1D polymeric chains in a 3D stacked chain supramolecular arrangement with apparent graph-set-motifs R11(8),C(4), and C(8). The Hirshfeld surface analysis corroborates well with X- ray data and explores all possible intermolecular interactions especially dominant N...H (16.6%) and H...S (7.3%) contacts. The MIC, MBC and in-vitro antibacterial study against Gram-positive (Staphylococcus aureus, Bacillus subtilis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) human pathogenic bacterial strains shows promising bactericidal activity. In-vitro antifungal study disclosing more activity against Aspergillus niger compared to Candida albicans at 50 mg/mL. DNA cleavage study (E. coli DNA) via Agarose gel electrophoresis shows DNA cleaving property of the title compound similar to that of H2O2 due to the suitable coordination of Cd (II) metal center.

    Amino-functionalized zr-based metal-organic tetrahedron for adsorptive removal of sulfonamide antibiotic in aqueous phase

    Liu, Zhao-YangTong, Ruo-MingChen, XinZhang, Yu-Teng...
    6页
    查看更多>>摘要:An amino-functionalized Zr-based metal-organic tetrahedron (denoted as ZrT-1-NH2) was synthesized under solvothermal conditions. In addition, the adsorption performances of ZrT-1-NH2 for sulfachloropyridazine (SCP) from aqueous solution were investigated. Moreover, the experimental results revealed that ZrT-1-NH2 has adsorption performance for SCP. The adsorption kinetic data were best fitted with the pseudo second order model. Furthermore, a plausible adsorption mechanism was proposed.

    Rare earth ion Nd3+ promotes production of cellulose ethanol by Clostridium thermocellum ATCC 27405

    Wang, YaboHu, JianhuaLi, YongliLiu, Zhanying...
    10页
    查看更多>>摘要:Clostridium thermocellum can directly produce ethanol from cellulose by consolidated bioprocessing. We studied how rare earth ions impact the ethanol titer and found that Nd3+ can significantly increase the production of ethanol from cellulose by C. thermocellum ATCC 27405. With the addition of 10 6 M Nd3+ in the initial incubation, the ethanol titer increased significantly, but the cellulose degradation ratio and cell growth did not change significantly. The intracellular distribution of Nd3+ was determined. Most Nd3+ was located on the surface of the cell wall. Nd3+ increased cell permeability, which was one of the reasons for the ethanol titer increased. We further explored the underlying mechanism from the perspective of key enzymes in the ethanol synthesis pathway. The enzyme activity and enzyme expression level of alcohol dehydrogenase (ADH) of strain C1 with added Nd3+ were lower than those of the original strain C0. However, both the enzyme activity and enzyme expression levels of acetaldehyde dehydrogenase (ALDH), pyruvate-ferredoxin oxidoreductase (PFO) and 6-phosphofructokinase (PFK) were increased. This rule was still valid for the sixth-generation strain C2 with Nd3+ removed. It was verified that the increase in the expression level of ALDH was not caused by the mutation of the ALDH promoter sequence. This research explored the key factors that limited the titer of cellulose ethanol in consolidated bioprocessing from an unconventional perspective and provided a new strategy for improving cellulose ethanol production.

    Crystal structures of three transition metal complexes with salicylaldehyde-4-hydroxy phenylacetyl acylhydrazone and their interactions with CT-DNA and BSA

    Huang, Dong-shengLiu, Xiang-rongZhao, Shun-shengYang, Zai-wen...
    12页
    查看更多>>摘要:A salicylaldehyde-4-hydroxy phenyl acetyl acyl hydrazone (C15H14N2O3, HL) and its three complexes ([CuLPy]NO3 (1), [CuLCl(EtOH)] (2) and [CoL2]NO3 center dot EtOH, (3)) were synthesized. The single crystal X-ray diffraction results of 1, 2 and 3 showed that the coordination atoms (N and O atoms) in the complexes exhibited four-coordinated pyramidal, five-coordinated and six-coordinated octahedral geometries centered on the metal ions, respectively. TG-DTG techniques illustrated that the maximum thermal decomposition peak temperatures of these compounds were all higher than 200 celcius, exhibiting strong thermal stabilities. All four compounds, HL, 1, 2 and 3, quenched the intrinsic fluorescence of BSA by means of static processes, as investigated by fluorescence spectra, which suggested that these compounds could effectively combine with BSA to form non-fluorescent ground state complexes. The UV-vis spectra showed that HL, 1, 2 and 3 effectively combined with CT-DNA through intercalative modes. Microcalorimetry tests indicated that the interaction processes of HL, 1 and 2 with BSA and CT-DNA were all spontaneously exothermic and entropy reducing, and each of the interaction durations was within 50 min. The interactions of the four compounds with BSA and CTDNA were also simulated by the molecular docking method, showing that the four compounds had hydrogen bonds and hydrophobic interactions with BSA and CT-DNA. The antibacterial activities of HL, 1, 2 and 3 against S. aureus, P. aeruginosa, B. subtilis and E. coli were determined, revealing that 1 and 2 exhibit stronger inhibition activities against P. aeruginosa than gentamicin sulfate. Complexes 1 and 2 are potential alternative drugs to gentamicin sulfate in the future.

    Synthesis, characterization, crystallographic structure, theoretical studies, and in vitro cytotoxicity assessment of two Gd(III) and Ce(IV) complexes containing pyridine-2,6-dicarboxylate

    Zohrevandi, MinaAbdolmaleki, SaraGhadermazi, MohammadGholiee, Yasin...
    9页
    查看更多>>摘要:This paper reports the synthesis of two complexes through one-pot reactions of pyridine-2,6-dicarboxylic acid (pydcH2), phenanthroline, and 2-aminopyridine, with Gd(NO3)3.6H2O and Ce (NO3)3.6H2O metal salts. The new coordination complexes C1 and C2 were identified by spectroscopic methods. The complexes were characterized by X-ray crystallography. The nature of metal-ligand interactions was studied theoretically using NBO and EDANOCV analyses. The results showed that the contribution of electrostatic interactions in both complexes is considerably larger than that of orbital. However, the contribution of orbital interactions in [CeL3]2-, is more than that in [GdL3]3- (28.8% vs. 21.8%). In following, the cytotoxic effect of synthetic complexes was investigated in vitro using oxaliplatin as a standard against three cancer cell lines including human breast cancer (MCF7), human colon adenocarcinoma (HT29), human lymphocyte (HL60) and also one normal cell, human foreskin fibroblast (HFF). The most significant inhibition activity was observed by both C1 (IC50 = 80.7 mu M, Viability inhibition = 83.41%) and C2 (IC50 = 98.3 mu M, Viability inhibition = 77.19%) toward the MCF7 cell line.

    Speciation study and biological activity of copper (II) complexes with picolinic and 6-methylpicolinic acid with different components of blood serum of low molecular mass in KNO3 1.0 mol.L-1 at 25 C-degrees

    Del Carpio, EdgarSerrano, Maria L.Hernandez, LinoMadden, Waleska...
    12页
    查看更多>>摘要:In the present work, the chemical speciation of ternary complexes of copper (II) with picolinic acid and 6-methylpicolinic acid and different ligands, such as, components of the blood plasma of low molecular mass (lactic acid, oxalic acid, citric acid, and phosphoric acid) were studied by measurements of emf(H) in KNO3 1.00 molL- 1. Potentiometric studies showed a predilection towards the formation of ternary species in solution, except for the copper (II)-picolinate-phosphate systems. The biological activity of the binary and ternary complexes isolated in situ, against reactive oxygen species was studied showing a concentration-dependent effect due to a possible mechanism of electron transfer. Finally, for the complexes Cu(Pic)2 and for the ligands were studied the ligand-receptor interaction on a PI3k of human origin by molecular docking, showing that, by themselves, the ligands are not capable of interacting with the active site of the enzyme. The metallic center is fundamental to generate reversible electrostatic interactions, that can be key to the indirect hypoglycemic effect exhibited by the Cu(Pic)2 complex reported in the literature.

    B-F bonding and reactivity analysis of mono- and perfluoro-substituted derivatives of closo-borate anions (6,10,12): A computational study

    Klyukin, Ilya N.Vlasova, Yuliya S.Novikov, Alexander S.Zhdanov, Andrey P....
    9页
    查看更多>>摘要:A theoretical study of the mono- and perfluoro-substituted derivatives of closo-borate anions with the general form [BnHn-1F]2- and [BnFn]2-, n = 6, 10, 12, was carried out. The main features of B-F bonds in selected molecular species were investigated using a number of general approaches (QTAIM, NBO, ELF). Atomic charges were estimated using AIM, NBO and Hirshfeld approaches. Global and local reactivity indices were calculated using Conceptual DFT theory.