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Structure and antimycobacterial activity of the novel organometallic [Pd(C-bzan)(SCN)(dppp)] compound

Ferreira, Janaina G.; Stevanato, Alessandra; Santana, Anderson M.; Mauro, Antonio E.; Netto, Adelino V. G.; Frem, Regina C. G.; Pavan, Fernando R.; Leite, Clarice Q. F.; Santos, Regina H. A.
Fonte: ELSEVIER SCIENCE BV; AMSTERDAM Publicador: ELSEVIER SCIENCE BV; AMSTERDAM
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
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The organometallic compound [Pd(C-bzan)(SCN)(dppp)] {bzan = N-benzylideneaniline, dppp = 1,3-bis(diphenylphosphino)propane} was synthesized and characterized by elemental analyses, infrared and H-1 and P-31(H-1) NMR spectroscopies. The crystal and molecular structures of the title complex were determined by single-crystal X-ray diffraction techniques. In vitro antimycobacterial evaluation demonstrated that the compound [Pd(C-bzan)(SCN)(dppp)] displayed a MIC of 5.15 mu M, which is superior than those values found for some commonly used anti-TB drugs and other Pd(II) complexes. (C) 2012 Elsevier B.V. All rights reserved.; CNPq; CNPq; FAPESP; FAPESP; CAPES; CAPES

Structure and antimycobacterial activity of the novel organometallic [Pd(C-bzan)(SCN)(dppp)] compound

Ferreira, Janaina G.; Stevanato, Alessandra; Santana, Anderson M.; Mauro, Antonio E.; Netto, Adelino V. G.; Frem, Regina C. G.; Pavan, Fernando R.; Leite, Clarice Q. F.; Santos, Regina H. A.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 63-66
ENG
Relevância na Pesquisa
503.03555%
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); The organometallic compound [Pd(C-bzan)(SCN)(dppp)] {bzan = N-benzylideneaniline, dppp = 1,3-bis(diphenylphosphino)propane} was synthesized and characterized by elemental analyses, infrared and H-1 and P-31(H-1) NMR spectroscopies. The crystal and molecular structures of the title complex were determined by single-crystal X-ray diffraction techniques. In vitro antimycobacterial evaluation demonstrated that the compound [Pd(C-bzan)(SCN)(dppp)] displayed a MIC of 5.15 mu M, which is superior than those values found for some commonly used anti-TB drugs and other Pd(II) complexes. (C) 2012 Elsevier B.V. All rights reserved.

Ab initio study and NMR analysis of the complexion of citric acid with ion lithium

Sambrano, JR; Zampieri, M.; Ferreira, A. G.; Longo, Elson
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 309-318
ENG
Relevância na Pesquisa
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Quantum mechanics calculations at the ab initio HF/3-21G* level were carried out with Nuclear Magnetic Resonance (NMR) measurements to characterize citric acid and lithium interactions. The results indicate the formation of a tridentate organometallic compound with one lithium and one citric acid molecule and a tridentate and bidentate compound of two lithium atoms and one citric acid molecule. The results are in agreement with the experimental and theoretical data. (C) 1999 Elsevier B.V. B.V. All rights reserved.

Organometalico [MnCp(CO)3] ocluido em zeolito Y; Organometalic compound [MnCp(CO)3] occluded in zeolite Y

Ricardo Forner
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 16/12/2008 PT
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Esta tese teve como objetivo o estudo dos efeitos estéricos e eletrônicos dos zeólitos faujasita HY, LiY, NaY e CsY na estrutura, reatividade e comportamento térmico do organometálico [MnCp(CO)3]ocluído. As diversas formas alcalinas do zeólito Y foram preparadas por troca iônica no zeólito Na56Y comercial e os estudos das interações, do comportamento térmico e da reatividade do complexo ocluído nos zeólitos foram feitos por espectroscopia de infravermelho com transformada de Fourier (FTIR) em um sistema especialmente construído para essa finalidade. O organometálico [MnCp(CO)3] adsorvido nos zeólitos apresentou, no mínimo, cinco bandas nos espectros FTIR, que foram atribuídas a diferentes sítios de ancoramentos localizados na superfície e na supercavidade. A decomposição do convidado ocluído ocorre com velocidades maiores nos sítios de ancoramento que possuem interações cátion-carbonila mais fracas. Os espectros obtidos para a oclusão do organometálico em zeólitos parcialmente hidratados mostraram que as interações carbonilas-cátions no zeólito parcialmente hidratado são tão intensas quanto às interações do convidado no hospedeiro desidratado. Os cálculos computacionais, que simularam as interações entre o zeólito e o organometálico...

A supramolecular zigzag chain of organometallic dipoles mediated by PF6 2- anions

Duarte, M. Teresa; Piedade, M. Fátima M.; Robalo, M. Paula; Teixeira, António P. S.; Garcia, M. Helena
Fonte: BLACKWELL PUBLISHING Publicador: BLACKWELL PUBLISHING
Tipo: Artigo de Revista Científica
ENG
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Complex {Fe( 5-cyclopentadienyl)(PMe3)[P(OPh)3](4–NCC6H4NO2)} [PF6] has been characterized by spectroscopic and X-ray diffraction in order to evaluate the tuning of the electron density at the metal center and the extension ofthe delocalization on the molecule due to the presence of phosphite and phosphine co-ligands. The compound crystallizes in the centrosymmetric space group P21/c which destroys the possibility of exhibiting any quadratic NLO properties. The packing shows a supramolecular zigzag chain of antiparalell dimmers connected via the PF6 anions with C—H—F −distances ranging from 2.389 (7) to 2.667 (6)°A . Each zigzag chain is composed by isomeric organometallic fragments containing either R or S molecules. These chains are connected through weak intermolecular interactions (C—H· · ·C) forming a two dimensional plane along [101].

Novel Tetrazine Organometallic Complexes for Nonlinear Optical Switching: a Combined Density Functional Theory and Experimental Study

Mendes, Paulo J.
Fonte: XXV International Conference on Organometallic Chemistry Publicador: XXV International Conference on Organometallic Chemistry
Tipo: Aula
ENG
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495.94504%
Over the past decade, mono- and bi- and oligonuclear organometallic complexes have been deal of great interest by material chemists and engineers due to their remarkable nonlinear optical (NLO), magnetic and electric properties. [1] They were furthermore envisaged as powerful candidates for quantum computing, molecular devices and more interestingly as molecular switches. The definition of molecular switch implies that a compound should have two interconvertable stable forms that have a significant difference in the magnitude of, at least, one of their physico-chemical properties. [2] In the case of organometallic complexes the most expedite way to achieve such interconversion is by redox means, where one takes advantage of the different oxidations states allowed by a single or multiple metal centers that interact with each other, and with the ligands therein. It is known that the choice of an appropriate π-bridging system between the metal centers is crucial to obtain the adequate electronic environment for efficient metal-to-metal and metal-to-ligand interactions, and hence fine tune the optical, electric and magnetic macroscopic properties. Mixed-valance metal complexes from group VIII, particular Fe(II)/Fe(III) and Ru(II)/Ru(III) systems [3...

A novel Osmium-based compound targets the mitochondria and triggers ROS-dependent apoptosis in colon carcinoma

Maillet, A; Yadav, S; Loo, Y L; Sachaphibulkij, K; Pervaiz, S
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
376.63758%
Engagement of the mitochondrial-death amplification pathway is an essential component in chemotherapeutic execution of cancer cells. Therefore, identification of mitochondria-targeting agents has become an attractive avenue for novel drug discovery. Here, we report the anticancer activity of a novel Osmium-based organometallic compound (hereafter named Os) on different colorectal carcinoma cell lines. HCT116 cell line was highly sensitive to Os and displayed characteristic features of autophagy and apoptosis; however, inhibition of autophagy did not rescue cell death unlike the pan-caspase inhibitor z-VAD-fmk. Furthermore, Os significantly altered mitochondrial morphology, disrupted electron transport flux, decreased mitochondrial transmembrane potential and ATP levels, and triggered a significant increase in reactive oxygen species (ROS) production. Interestingly, the sensitivity of cell lines to Os was linked to its ability to induce mitochondrial ROS production (HCT116 and RKO) as HT29 and SW620 cell lines that failed to show an increase in ROS were resistant to the death-inducing activity of Os. Finally, intra-peritoneal injections of Os significantly inhibited tumor formation in a murine model of HCT116 carcinogenesis, and pretreatment with Os significantly enhanced tumor cell sensitivity to cisplatin and doxorubicin. These data highlight the mitochondria-targeting activity of this novel compound with potent anticancer effect in vitro and in vivo...

Synthesis of organometallic ruthenium(II) complexes with strong activity against several human cancer cell lines

Mendes, Paulo J.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
ENG
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A new family of "RuCp" (Cp=η(5)-C(5)H(5)) derivatives with bidentate N,O and N,N'-heteroaromatic ligands revealed outstanding cytotoxic properties against several human cell lines namely, A2780, A2780CisR, HT29, MCF7, MDAMB231, and PC3. IC(50) values were much lower than those found for cisplatin. Crystal structure of compound 4 was determined by X-ray diffraction studies. Density functional theory (DFT) calculations performed for compound 1 showed electronic flow from the ruthenium center to the coordinated bidentate ligand, in agreement with the electrochemical studies and the existence of a metal-to-ligand charge-transfer (MLCT) band evidenced by spectroscopic data.

First-principles study of an organometallic S=1/2 kagome compound

Liu, Zheng; Mei, Jia-Wei; Liu, Feng
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
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Cu(1,3-benzenedicarboxylate) [Cu(1,3-bdc)] contains structurally perfect kagom\'{e} planes formed by Cu$^{2+}$ ions without the presence of diamagnetic defects. This organometallic compound should have served as a precious platform to explore quantum frustrated magnetism, yet the experimental results so far are mysterious, leading to questions such as "Is Cu(1,3-bdc) just a trivial weak ferromagnet?". Using the the density functional theory, we have systematically studied the electronic and magnetic properties of Cu(1,3-bdc), putting forth a theoretical basis to clarify this novel material. We present numerical evidences of a dominating antiferromagnetic (AFM) exchange between nearest-neighbor (NN) Cu$^{2+}$ as experimentally extracted from the high-temperature susceptibility data. We further show that beyond the NN AFM exchange, the additional interactions in Cu(1,3-bdc) have similar strength as those in the well-studied kagom\'{e} antiferromagnet, Herbertsmithite, by designing a comparative study. In the end, the origin of the phase transition and FM signals observed under low temperature is discussed based on the DFT results.; Comment: 9 pages, 5 figures, 2 tables

Synthesis and structural characterization of 2Dioxane.2H2O.CuCl2: metal-organic compound with Heisenberg antiferromagnetic S=1/2 chains

Hong, Tao; Custelcean, R.; Sales, B. C.; Roessli, B.; Singh, D. K.; Zheludev, A.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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372.2405%
A novel organometallic compound 2Dioxane.CuCl2.2H2O has been synthesized and structurally characterized by X-ray crystallography. Magnetic susceptibility and zero-field inelastic neutron scattering have also been used to study its magnetic properties. It turns out that this material is a weakly coupled one-dimensional S=1/2 Heisenberg antiferromagnetic chain system with chain direction along the crystallographic c axis and the nearest-neighbor intra-chain exchange constant J=0.85(4) meV. The next-nearest-neighbor inter-chain exchange constant J' is also estimated to be 0.05 meV. The observed magnetic excitation spectrum from inelastic neutron scattering is in excellent agreement with numerical calculations based on the Muller ansatz.; Comment: 4 pages; 5 figures

Organometallic complexes for nonlinear optics Part 32: Synthesis, optical spectroscopy and theoretical studies of some osmium alkynyl complexes

Morrall, Joseph; Powell, Clem; Stranger, Robert; Cifuentes, Marie; Humphrey, Mark; Heath, Graham
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
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The complexes trans-[Os(C≡CPh)Cl(dppe)2] (1), trans-[Os(4-C≡CC6H4C≡CPh) Cl(dppe)2] (2), and 1,3,5-{trans-[OsCl(dppe)2 (4-C≡CC6H4 C≡C)]}3C6H3 (3) have been prepared. Cyclic voltammetric studies reveal a quasi-reversible oxidation process for each

Organometallic complexes for nonlinear optics. Part 27. Syntheses and optical properties of some iron, ruthenium and osmium alkynyl complexes

Powell, Clem; Cifuentes, Marie; McDonagh, Andrew; Hurst, Stephanie; Lucas, Nigel; Delfs, Christopher; Stranger, Robert; Humphrey, Mark; Houbrechts, Stephan; Asselberghs, Inge; Persoons, Andre Pierre; Hockless, David
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
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379.39406%
The syntheses of the alkynyl complexes M(4-C≡CC6H4NO2)(dppe)(η-C 5H5) [M=Fe (1), Ru (2), Os (3)], Os(4-C≡CC6H4NO2)(PPh3) 2(η-C5H5) (4) and Ru(4-C≡CC6H4NO2)(CO)2 (η-C5H5) (5) are reported. Structural studies reveal a decrease in Ru-C(1) distance o

Expect the unexpected. Isolation and characterisation of some unusual organometallic gold(I) complexes

Bhargava, Suresh Kumar; Mohr, Fabian; Willis, Anthony
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
379.39406%
The reaction of equimolar amounts of 2-Li-3-MeC6H3PPh2 and [AuBr(AsPh3)] gives a mixture of the cyclometallated digold(I) complex [Au2(μ-6-MeC6H3-2-PPh2) 2] and the 'half-cyclometallated' complex [(Ph3As)Au(μ-6-MeC6H3-2-PPh 2)AuBr] (1). This complex rep

Organometallic Complexes for Nonlinear Optics. Part 29. Quadratic and Cubic Hyperpolarizabilities of Stilbenylethynyl-gold and -ruthenium Complexes

Hurst, Stephanie; Lucas, Nigel; Humphrey, Mark; Isoshima, Takashi; Wostyn, Kurt; Asselberghs, Inge; Clays, Koen Jan; Persoons, Andre Pierre; Samoc, Marek; Luther-Davies, Barry
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
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379.39406%
The compounds (E)-4-XC≡CC6H4CH=CHPh [X=SiMe3 (1), H (2)], 1,3,5-{(E)-4-XC6H 4CH=CH}3C6H3 [X=I (3), C≡CSiMe3 (4), C≡CH (5)], [Au{(E)-4-C≡CC 6H4CH=CHPh}(L)] [L=PPh3 (6), PMe3 (7)], [Au(4-C≡CC6H4C≡CPh)(L)] [L=PPh 3 (8), PMe3 (9)], 1,3,5-[(Ph3P)Au

Organometallic Complexes for Nonlinear Optics 16. Second and Third Order Optical Nonlinearities of Octopolar Alkynylruthenium Complexes

McDonagh, Andrew; Humphrey, Mark; Samoc, Marek; Luther-Davies, Barry; Houbrechts, Stephan; Wada, Tatsuo; Sasabe, Hiroyuki; Persoons, Andre Pierre
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
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Antitumor metallocenes: structure-activity studies and interactions with biomolecules

Harding, Margaret; Mokdsi, George
Fonte: Bentham Science Publishers Ltd Publicador: Bentham Science Publishers Ltd
Tipo: Artigo de Revista Científica
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The metallocene dihalides are a relatively new class of small, hydrophobic organometallic anticancer agents that exhibit antitumour properties against numerous cell lines including leukemias P388 and L1210, colon 38 and Lewis lung carcinomas, B16 melanoma, solid and fluid Ehrlich ascites tumours and several human colon and lung carcinomas transplanted into athymic mice. Titanocene dichloride I has been the most widely studied metallocene and the drug is currently in phase II clinical trials. Formation of metallocene-DNA complexes has been implicated in the mechanism of antitumour properties of the metallocenes, as both titanocene dichloride 1 and vanadocene dichloride 2 inhibit DNA and RNA synthesis, and titanium and vanadium accumulate in nucleic acid-rich regions of tumour cells. However, in contrast to the well characterized platinum-based anticancer drugs, the active species responsible for antitumour activity in vivo has not been identified and the mechanism whereby irreparable DNA damage and/or structural modification of DNA or other cellular targets occurs is poorly understood. This review will focus on recent studies that have been carried out in order to identify the biologically active species and more fully understand the molecular level mechanism of action of the metallocene dihalides. Studies with nucleotides...

Organometallic complexes for nonlinear optics Part 31. Cubic hyperpolarizabilities of ferrocenyl-linked gold and ruthenium complexes

Hurst, Stephanie; Humphrey, Mark; Morrall, Joseph; Cifuentes, Marie; Samoc, Marek; Luther-Davies, Barry; Heath, Graham; Willis, Anthony
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
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379.39406%
The complexes [Fe{η-C5H4-(E)-CH= CH-4-C6H4C≡CX}2] [X=SiMe3 (1), H (2), Au(PCy3) (3), Au(PPh3) (4), Au(PMe3) (5), RuCl(dppm)2 (7), RuCl(dppe)2 (8)] and [Fe{η-C5H4-(E)-CH= CH-4-C6H4CH≡CRuCl} (dppm)2}2](PF6)2 (6) have been prepared and the identities o

Disproportionation and Nuclease Activity of Bis[2-ethyl-2-hydroxybutanoato(2-)]oxochromate(V) in Neutral Aqueous Solutions

Levina, Aviva; Lay, Peter; Dixon, Nicholas
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
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372.2405%
Complex 1, [Cr(V)O(ehba)2]- (ehba = 2-ethyl-2-hydroxybutanoate(2-)) is the most studied model compound of relevance to the biological activity of Cr(V) with regard to Cr-induced cancers. The first detailed kinetic study of disproportionation of 1 under neutral pH conditions (pH 6.0-8.0, [NaClO4] = 1.0 M, 37 °C) is reported. Kinetic data were collected by stopped-flow and conventional UV-vis spectroscopies and processed by the global analysis method. The disproportionation, which follows the stoichiometry 3Cr(V) → 2Cr(VI) + Cr(III) (1), leads to release of 5 mol of H+/3 mol of Cr(V). Reaction 1 is accelerated by phosphate, but is not affected by acetate, HEPES, or Tris buffers. Initial rates of Cr(V) decay are directly proportional to [Cr(V)]0 (0.020-1.0 mM); they increase with an increase in the pH values and decrease in the presence of a large excess of ehba ligand. The first direct evidence for the formation of Cr(IV) intermediates in reaction 1 has been obtained; however, their UV-vis spectral properties were different from those of the well-characterized Cr(IV)-ehba complexes. The Cr(III) products of reaction 1 in phosphate buffers differ from those in the other buffers. A mechanism is proposed for reaction 1 on the basis of kinetic modeling. Influences of the reaction time and conditions on the extent of plasmid DNA cleavage induced by 1 have been studied under conditions corresponding to those of the kinetic studies. A comparison of the kinetic and DNA cleavage results has shown that direct interaction of 1 with the phosphate backbone of DNA is the most likely first step in the mechanism of DNA cleavage in neutral media. Small additions of Mn(II) ((0.01-0.1)[Cr(V)]0) did not affect the rate and stoichiometry of reaction 1...

Organometallic Anticancer Agents: Cellular Uptake and Cytotoxicity Studies on Thiol Derivatives of the Antitumor Agent Molybdocene Dichloride

Waern, Jenny B; Dillon, Carolyn; Harding, Margaret
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
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The effect of aqueous solubility, charge, and lability of four thiol derivatives of the antitumor metallocene molybdocene dichloride (Cp 2MoCl2) on the cell uptake and cytotoxicity against V79 Chinese hamster lung cells has been determined. Addition of 4-thiol-2,3,5,6- tetrafluorobenzoic acid, 1-thio-β-D-glucose, and 1-thio-2,3,4,5- tetraacetyl-β-D-glucose to aqueous solutions of molybdocene dichloride afforded the corresponding metallocenes in which the deprotonated thiols are coordinated to the metal center. These metallocenes were studied, along with the previously reported glutathione derivative Cp2Mo(GS)2, which has been proposed to be formed from molybdocene dichloride in blood plasma. In contrast to Cp2MoCl2 which rapidly loses the chloride ligands to form a positively charged aquated complex at pH 7, the thiol derivatives are stable to ligand hydrolysis in 50 mM salt at 37°C for 24 h. Cytotoxicity values determined by a modified 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay gave an IC50 value of 350 μM for molybdocene dichloride with V79 cells, with similar values obtained with human breast MCF-7 (620 μM) and ovarian 2008 (700 μM) cell lines. The water-soluble thiol derivatives were not cytotoxic...

Dispersion of the Third-Order Nonlinear Optical Properties of an Organometallic Dendrimer

Powell, Clem; Morrall, Joseph; Ward, Simone; Cifuentes, Marie; Notaras, Eleni; Samoc, Marek; Humphrey, Mark
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
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The dispersion of cubic nonlinearity in the organometallic dendrimer 1,3,5-(3,5-{trans-[(dppe)2(4-O2NC6H4C≡C)RuC≡C]}2C6H3C≡CC6H4-4-C≡C)3C6H3 can be understood in terms of an interplay of two-photon absorption and absorption saturation. Simple disp