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41.
Condé Camila A. S. R. De Almeida Mauro V. Da Silva Gabrielle dos Santos Sodré Milena Barenco Pires de Abreu Rodrigues Juliany Cola Fernandes Navarro Maribel 《Transition Metal Chemistry》2022,47(4-5):147-156
Transition Metal Chemistry - A new set of copper- and zinc-diamine (N-alkylated (L1) and N,N'-dialkylated (L2)) complexes, [Cu(L1)2(NO3)2] (1), [Cu(L1)2(Cl)2].5H2O (2), [Cu(L2)2(NO3)2] (3),... 相似文献
42.
A partial difference set in a finite group satisfying and corresponds to an undirected strongly regular Cayley graph . While the case when is abelian has been thoroughly studied, there are comparatively few results when is nonabelian. In this paper, we provide restrictions on the parameters of a partial difference set that apply to both abelian and nonabelian groups and are especially effective in groups with a nontrivial center. In particular, these results apply to ‐groups, and we are able to rule out the existence of partial difference sets in many instances. 相似文献
43.
Richard Harrington Gabrielle C. Miles Anthony R. West 《Journal of solid state chemistry》2008,181(2):334-339
Zn7Sb2O12 forms a full range of Co-containing α solid solutions, Zn7−xCoxSb2O12, with an inverse-spinel structure at high temperature. At low temperatures for x<2, the solid solutions transform into the low temperature β-polymorph. For x=0, the β→α transition occurs at 1225±25 °C; the transition temperature decreases with increasing x. At high x and low temperatures, α solid solutions are formed but are non-stoichiometric; the (Zn+Co):Sb ratio is >7:2 and the compensation for the deficiency in Sb is attributed to the partial oxidation of Co2+ to Co3+. From Rietveld refinements using ND data, Co occupies both octahedral and tetrahedral sites at intermediate values of x, but an octahedral preference attributed to crystal field stabilisation, causes the lattice parameter plot to deviate negatively from the Vegard's law. Sub-solidus compatibility relations in the ternary system ZnO-Sb2O5-CoO have been determined at 1100 °C for the compositions containing ?50% Sb2O5. 相似文献
44.
F Provencher N Bérubé JF Laprade G Simard J Tant V de Halleux Y Geerts C Silva M Côté 《The Journal of chemical physics》2012,137(3):034706
We examine the interdependence of structural and electronic properties of two substituted pyrene crystals by means of combined spectroscopic probes and density-functional theory calculations. Substituted pyrenes are useful model systems to unravel the interplay of crystal structure and electronic properties in organic semiconductors. To study the effect of steric encumbrance on the crystalline arrangement of two 1,3,6,8-tetraalkynylpyrene derivatives, one features linear n-hexyl side groups while the other contains branched trimethylsilyl groups. Both derivatives form triclinic crystal structures when grown from solution, but the electronic dispersion behavior is significantly different due to differences in π-π overlap along the π-stacking axis. Both systems display dispersion of around 0.45 eV in the valence band, suggesting a high intrinsic hole mobility. However, the direction of the dispersion is different: it is primarily along the π-stacking axis in the trimethylsilyl-substituted derivative, but less aligned with this crystal axis in the hexyl-substituted molecule. This is a direct consequence of the differences in co-facial π electron overlap revealed by the crystallographic studies. We find that photophysical defects, ascribed to excimer-like states, point to the importance of localized trap states. 相似文献
45.
Ali NA Sharopov FS Alhaj M Hill GM Porzel A Arnold N Setzer WN Schmidt J Wessjohann L 《Natural product communications》2012,7(2):257-260
The chemical composition of the essential oil obtained from the leaves of Pulicaria undulata Gamal Ed Din (syn P. orientalis sensu Schwartz and P. jaubertii Gamal Ed Din) was analyzed by GC-MS. Major compounds of P. undulata oil were the oxygenated monoterpenenes, carvotanacetone (91.4%) and 2,5-dimethoxy-p-cymene (2.6.%). The antimicrobial activity of the essential oil was evaluated against six microorganisms, Escherichia coli Pseudomonas aeruginosa, Staphylococcus aureus, methicillin-resistant S. aureus, Bacillus subtilis, and Candida albicans, using disc diffusion and broth microdilution methods. The oil showed the strongest bactericidal activity against Staphylococcus aureus and methicillin-resistant S. aureus, as well as Candida albicans. The essential oil showed moderate cytotoxic activity against MCF-7 breast tumor cells, with an IC50 of 64.6 +/- 13.7 microg/mL. Bioautographic assays were used to evaluate the acetylcholinesterase inhibitory effect as well as antifungal activity of the oil against Cladosporium cucumerinum. 相似文献
46.
Liu R Zhang M Wyche TP Winston-McPherson GN Bugni TS Tang W 《Angewandte Chemie (International ed. in English)》2012,51(30):7503-7506
47.
Gabriela Aldea Gabrielle C. Chitanu Jacques Delaunay Jean‐Michel Nunzi Bogdan C. Simionescu Jack Cousseau 《Journal of polymer science. Part A, Polymer chemistry》2005,43(23):5814-5822
Starting from the synthesis of a new methanofullerene derivative bearing an alcohol group, we report on the preparation of a water‐soluble, fullerene‐pendant copolymer. This multifunctional, C60‐pendant maleic anhydride copolymer was characterized by conductometric titration, Fourier transform infrared and ultraviolet spectroscopy, thermogravimetric analysis, and cyclic voltammetry. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5814–5822, 2005 相似文献
48.
Gabrielle Villari Jr. 《Journal of Differential Equations》2007,234(1):337-338
49.
Agnès Rolland-Sabaté Sophie Guilois Florent Grimaud Christine Lancelon-Pin Xavier Roussel Sandrine Laguerre Anders Viksø-Nielsen Jean-Luc Putaux Christophe D’Hulst Gabrielle Potocki-Véronèse Alain Buléon 《Analytical and bioanalytical chemistry》2014,406(6):1607-1618
Asymmetrical flow field flow fractionation (AF4) has proven to be a very powerful and quantitative method for the determination of the macromolecular structure of high molar mass branched biopolymers, when coupled with multi-angle laser light scattering (MALLS). This work describes a detailed investigation of the macromolecular structure of native glycogens and hyperbranched α-glucans (HBPs), with average molar mass ranging from 2?×?106 to 4.3?×?107 g mol?1, which are not well fractionated by means of classical size-exclusion chromatography. HBPs were enzymatically produced from sucrose by the tandem action of an amylosucrase and a branching enzyme mimicking in vitro the elongation and branching steps involved in glycogen biosynthesis. Size and molar mass distributions were studied by AF4, coupled with online quasi-elastic light scattering (QELS) and transmission electron microscopy. AF4-MALLS-QELS has shown a remarkable agreement between hydrodynamic radii obtained by online QELS and by AF4 theory in normal mode with constant cross flow. Molar mass, size, and dispersity were shown to significantly increase with initial sucrose concentration, and to decrease when the branching enzyme activity increases. Several populations with different size range were observed: the amount of small size molecules decreasing with increasing sucrose concentration. The spherical and dense global conformation thus highlighted was partly similar to native glycogens. A more detailed study of HBPs synthesized from low and high initial sucrose concentrations was performed using complementary enzymatic hydrolysis of external chains and chromatography. It emphasized a more homogeneous branching pattern than native glycogens with a denser core and shorter external chains. Figure
Characterization of hyperbranched glycopolymers. TEM Transmission electron microscopy. AF4-MALLS-QELS Asymmetrical flow field flow fractionation coupled with multi-angle laser-light scattering and quasi-elastic light scattering 相似文献
50.
Gabrielle M. Risica Veacheslav Vieru Branford O. Wilkins Trevor P. Latendresse Joseph H. Reibenspies Nattamai S. Bhuvanesh Gregory P. Wylie Liviu F. Chibotaru Michael Nippe 《Angewandte Chemie (International ed. in English)》2020,59(32):13335-13340
We report the first f‐block‐ruthenocenophane complexes 1 (Dy) and 2 (Tb) and provide a comparative discussion of their magnetic structure with respect to earlier reported ferrocenophane analogues. While axial elongation of the rare trigonal‐prismatic geometry stabilizes the magnetic ground state in the case of Dy3+ and results in a larger barrier to magnetization reversal (U), a decrease in U is observed for the case of Tb3+. 相似文献