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191.
J. R. Cain A. A. Noyes und W. C. Bray 《Fresenius' Journal of Analytical Chemistry》1914,53(2):125-126
Ohne Zusammenfassung 相似文献
192.
M. W. Bray T. M. Andrews C. F. Cross E. J. Bevan H. Jentgen O. Dischendorfer W. Traube A. Biltz L. Kalb V. Schoeller F. A. Bühler und J. König 《Fresenius' Journal of Analytical Chemistry》1928,74(7):265-268
Ohne Zusammenfassung 相似文献
193.
194.
W. Geilmann F. W. Wrigge R. Fricke F. W. Kriesel M. Picon P. A. Shaw A. A. Noyes W. C. Bray E. B. Spear M. W. Troitzki L. Fernandes P. W. Selwood H. H. Willard J. W. Neckers H. C. Kremers B. S. Hopkins L. L. Quill J. Stérba-Boehm V. Matula F. P. Treadwell O. Tomicek E. Bauer A. Glaessner O. Sackur W. Taegener J. M. Kolthoff A. Job O. Tomiceck 《Analytical and bioanalytical chemistry》1934,98(11-12):429-446
195.
J. M. Kolthoff F. G. Hills V. Lampe H. Beckurts F. Mayer L. Moser J. Singer G. Wynkoop A. Brukl O. Ruff E. Stephan M. Frommes M. Nießner W. F. Hillebrand G. E. F. Lundell Hellmut Fischer Grete Leopoldi A. Cissarz H. Schneiderhöhn E. Zintl J. Kassler H. B. Knowles H. V. Churchill R. W. Bridges M. F. Lee E. Dittler F. Kirnbauer B. E. Dixon Noyes Bray F. List W. Maxymowicz und F. Spindeck 《Fresenius' Journal of Analytical Chemistry》1933,93(7-8):285-307
Ohne Zusammenfassung 相似文献
196.
The reaction of uranyl nitrate with asymmetric [3O, N] Schiff base ligands in the presence of base yields dinuclear uranyl complexes, [UO2(HL1)]2.DMF (1), [UO2(HL2)]2.2DMF.H2O (2), and [UO2(HL3)]2.2DMF (3) with 3-(2-hydroxybenzylideneamino)propane-1,2-diol (H3L1), 4-((2,3-dihydroxypropylimino)methyl)benzene-1,3-diol (H3L2), and 3-(3,5-di-tert-butyl-2-hydroxybenzylideneamino)propane-1,2-diol (H3L3), respectively. All complexes exhibit a symmetric U2O2 core featuring a distorted pentagonal bipyramidal geometry around each uranyl center. The hydroxyl groups on the ligands are attached to the uranyl ion in chelating, bridging, and coordinate covalent bonds. Distortion in the backbone is more pronounced in 1, where the phenyl groups are on the same side of the planar U2O2 core. The phenyl groups are present on the opposite side of U2O2 core in 2 and 3 due to electronic and steric effects. A similar hydrogen-bonding pattern is observed in the solid-state structures of 1 and 3 with terminal hydroxyl groups and DMF molecules, resulting in discrete molecules. Free aryl hydroxyl groups and water molecules in 2 give rise to a two-dimensional network with water molecules in the channels of an extended corrugated sheet structure. Compound 1 in the presence of excess Ag(NO3) yields {[(UO2)(NO3)(C6H4OCOO)](NH(CH2CH3)3)}2 (4), where the geometry around the uranyl center is hexagonal bipyrimidal. Two-phase extraction studies of uranium from aqueous media employing H3L3 indicate 99% reduction of uranyl ion at higher pH. 相似文献
197.
We report a first-principles, periodic supercell analysis of oxygen adsorption, diffusion, and dissociation at the kinked Pt(321) surface. Binding energies and binding site preferences of isolated oxygen atoms and molecules have been determined, and we show that both atomic and molecular oxygen prefer binding in bridge sites involving coordinatively unsaturated kink Pt atoms. Binding energies of atomic and molecular oxygen in different sites correlate well with the average metallic Pt coordination number of Pt atoms forming each site, although differences exist between adsorbates in symmetrically similar sites due to the inherent chirality of the surface. Atomic O in the strongest binding bridge sites experiences relatively small energy barriers for diffusion to neighboring sites compared to O on Pt(111). However, due to the structure of the surface, O diffusion is only rapid between different sites around the kink Pt atom, whereas the effective long-range tracer diffusion, as determined from a simple course-grain model, is shown to be anisotropic and slower than on the Pt(111) surface. Four dissociation pathways for O(2) at low coverage are also reported and found to be in agreement with experimental observations of facile dissociation, even at low temperature. 相似文献
198.
Marino ST Stachurska-Buczek D Huggins DA Krywult BM Sheehan CS Nguyen T Choi N Parsons JG Griffiths PG James IW Bray AM White JM Boyce RS 《Molecules (Basel, Switzerland)》2004,9(6):405-426
In the past decade there has been a significant growth in the sales of pharmaceutical drugs worldwide, but more importantly there has been a dramatic growth in the sales of single enantiomer drugs. The pharmaceutical industry has a rising demand for chiral intermediates and research reagents because of the continuing imperative to improve drug efficacy. This in turn impacts on researchers involved in preclinical discovery work. Besides traditional chiral pool and resolution of racemates as sources of chiral building blocks, many new synthetic methods including a great variety of catalytic reactions have been developed which facilitate the production of complex chiral drug candidates for clinical trials. The most ambitious technique is to synthesise homochiral compounds from non-chiral starting materials using chiral metal catalysts and related chemistry. Examples of the synthesis of chiral building blocks from achiral materials utilizing asymmetric hydrogenation and asymmetric epoxidation are presented. 相似文献
199.
200.
J. Hoszowska A. S. Kheifets M. Berset I. Bray W. Cao J.-Cl. Dousse K. Fennane M. Kav?i? Y. Kayser J. Szlachetko M. Szlachetko 《The European physical journal. Special topics》2009,169(1):23-27
We report on the investigation of the photon energy dependence of double 1s photoionization of light atoms and compare the
cross sections for hollow atom and He-like ion production. Measurements of the Kα hypersatellite x-ray spectra of Mg, Al,
and Si were carried out using the Fribourg high-resolution x-ray spectrometer installed at the ID21 and ID26 beam lines at
the ESRF. The double-to-single photoionization cross section ratios were derived as a function of the incident photon beam
energy and compared to convergent close-coupling (CCC) calculations for He-like ions. The dynamical electron-electron scattering
contribution to the DPI cross-sections was found to be more important for neutral atoms than for the He isoelectronic series. 相似文献