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排序方式: 共有157条查询结果,搜索用时 0 毫秒
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Isolda C. Mendes Juliana P. Moreira Antonio S. Mangrich Solange P. Balena Bernardo L. Rodrigues Heloisa Beraldo 《Polyhedron》2007
Five copper(II) complexes with N(4)-ortho, N(4)-meta and N(4)-para-tolyl thiosemicarbazones derived from 2-formyl and 2-acetylpyridine were obtained and thoroughly characterized. The crystal structure of N(4)-meta-tolyl-2-acetylpyridine thiosemicarbazone (H2Ac4mT) was determined, as well as that of its copper(II) complex [Cu(2Ac4mT)Cl], which contains an anionic ligand and a chloride in the coordination sphere of the metal. The in vitro antimicrobial activities of all thiosemicarbazones and their copper(II) complexes were tested against Salmonella typhimurium and Candida albicans. Upon coordination a substantial decrease in the minimum inhibitory concentration, from 225 to 1478 μmol L−1 for the thiosemicarbazones to 5–30 μmol L−1 for the complexes was observe against the growth of Salmonella typhimurium and from 0.7–26 to 0.3–7 μmol L−1 against the growth of C. albicans, suggesting that complexation to copper(II) could be an interesting strategy of dose reduction. 相似文献
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Emmanuel Zimmermman Moreira Luiz Alberto Beraldo de Moraes Marcos Nogueira Eberlin Yassuko Iamamoto Sofia Nikolaou 《Polyhedron》2008
The novel asymmetric metallo-organic triads cis- and trans-[B(4-py)BPFPH2{Ru3O(Ac)6(py)2}{Ru(bpy)2Cl}](PF6)2 (5a,b) for which cis- and trans-B(4-py)BPFPH2 = 5,10-bis(pentafluorophenyl)-15,20-bis(4-pyridyl)porphyrin and 5,15-bis(pentafluorophenyl)-10,20-bis(4-pyridyl)porphyrin, respectively; Ac = acetate; py = pyridine and bpy = 2,2′-bipyridine, as well as their corresponding monosubstituted dyads cis- and trans-[B(4-py)BPFPH2{Ru3O(Ac)6(py)2}]PF6 (4a,b) have been structurally characterized via electrospray ionization mass spectrometry (ESI-MS and ESI-MS/MS). The ESI-MS of dyads 4a,b display two characteristic Ru-multicomponent clusters of isotopologue ions corresponding to singly charged ions 4a,b+ of m/z 1629 and doubly charged ions [4a,b+H]2+ of m/z 815 and the triads 5a,b are detected by ESI-MS as the intact doubly charged cluster of isotopologue ions of m/z 1039 [5a,b]2+. The ESI-MS/MS of 4a,b+, [4a,b+H]2+ and [5a,b]2+ reveal characteristic dissociation pathways, which confirm the structural assignments providing additional information on the intrinsic binding strengths of the gaseous ions. Although the gas-phase behavior of each pair of isomers was rather similar, the less symmetric dyads 4a,b are distinguished via the 1H NMR spectral profile of the pyrrolic signals. Exploratory photophysical assays have shown that both modifying motifs alter the porphyrinic core emission profile, opening the possibility to use these asymmetric systems as photophysical devices. 相似文献
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We study the critical depinning current Jc versus the applied magnetic flux Phi, for quasiperiodic (QP) chains and 2D arrays of pinning centers placed on the nodes of a fivefold Penrose lattice. In QP chains, the peaks in Jc(Phi) are determined by a sequence of harmonics of the long and short segments of the chain. The critical current Jc(Phi) has a remarkable self-similarity. In 2D QP pinning arrays, we predict analytically and numerically the main features of Jc(Phi), and demonstrate that the Penrose lattice of pinning sites provides an enormous enhancement of Jc(Phi), even compared to triangular and random pinning site arrays. This huge increase in Jc(Phi) could be useful for applications. 相似文献
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Denise da Gama Jaén Batista Patrícia Bernardino da Silva Daniela R. Lachter Renata S. Silva Ricardo Q. Aucelio Sonia R.W. Louro Heloisa Beraldo Maria de Nazaré C. Soeiro Letícia R. Teixeira 《Polyhedron》2010
Thiosemicarbazones are known to be active against different pathogenic microorganisms including Trypanosoma cruzi, the etiological agent of Chagas disease. In the search for new therapeutic drugs against this illness, the complexes [Mn(H4NO2Fo4M)2Cl2] (1), [Mn(H4NO2Ac4M)2Cl2] (2) and [Mn(H4NO2Bz4M)2Cl2] (3) of N4-methyl-4-nitrobenzaldehyde thiosemicarbazone (H4NO2Fo4M), N4-methyl-4-nitroacetophenone thiosemicarbazone (H4NO2Ac4M) and N4-methyl-4-nitrobenzophenone thiosemicarbazone (H4NO2Bz4M) were obtained and screened in vitro against bloodstream and intracellular forms of T. cruzi. H4NO2Fo4M, H4NO2Ac4M and their Mn(II) complexes displayed poor effect on bloodstream trypomastigotes, with IC50 values ranging from 68 to >200 μM. However, although H4NO2Bz4M was also not active, its corresponding Mn(II) complex presented high effect on this T. cruzi form, with an IC50 value of 19 μM. The effect of complex (3), against trypomastigotes of T. cruzi supports further in vitro as well as in vivo studies. 相似文献