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[Cu2(μO2CCH3)4(H2O)2], [CuCO3·Cu(OH)2], [CoSO4·7H2O], [Co((+)-tartrate)], and [FeSO4·7H2O] react with excess racemic (±)- 1,1′-binaphthyl-2,2′-diyl hydrogen phosphate {(±)-PhosH} to give mononuclear CuII, CoII and FeII products. The cobalt product, [Co(CH3OH)4(H2O)2]((+)-Phos)((−)-Phos) ·2CH3OH·H2O (7), has been identified by X-ray diffraction. The high-spin, octahedral CoII atom is ligated by four equatorial methanol molecules and two axial water molecules. A (+)- and a (−)-Phos− ion are associated with each molecule of the complex but are not coordinated to the metal centre. For the other CoII, CuII and FeII samples of similar formulation to (7) it is also thought that the Phos− ions are not bonded directly to the metal. When some of the CuII and CoII samples are heated under high vacuum there is evidence that the Phos− ions are coordinated directly to the metals in the products. 相似文献
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Emmanuel N. Zevgolis Charalabos Zografidis Theodora Perraki Eamonn Devlin 《Journal of Thermal Analysis and Calorimetry》2010,100(1):133-139
This article refers to the mineralogical composition and phase transformations of Greek nickeliferous laterites and to their
metallurgical behaviour, during preheating and reduction with carbon monoxide. Transformation of goethite to hematite and
decomposition of chlorite and serpentine, were identified during preheating. Higher iron metallization was achieved for the
ore in which goethite is the main iron mineral and reduction goes up to 95%, whereas it goes up to 50% for the ore in which
hematite is the main iron mineral. The higher reducibility, however, seems to be due to the higher specific surface area of
the goethitic type of ore. 相似文献
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Zueva EM Sameera WM Piñero DM Chakraborty I Devlin E Baran P Lebruskova K Sanakis Y McGrady JE Raptis RG 《Inorganic chemistry》2011,50(3):1021-1029
Six [Fe(8)(μ(4)-O)(4)(μ-4-R-pyrazolato)(12)X(4)] complexes containing an identical Fe(8)(μ(4)-O)(4) core have been structurally characterized and studied by M?ssbauer spectroscopy. In each case, an inner μ(4)-O bridged Fe(III) cubane core is surrounded by four trigonal bipyramidal iron centers, the two distinct sites occurring in a 1:1 ratio. The M?ssbauer spectrum of each of the clusters consists of two quadrupole doublets, which, with one exception (X = NCS, R = H), overlap to give three absorption lines. The systematic variation of X and R causes significant changes in the M?ssbauer spectra. A comparison with values for the same clusters computed using density functional theory allows us to establish an unequivocal assignment of these peaks in terms of a nested model for the overlapping doublets. The changes in M?ssbauer parameters (both experimental and computed) for the 1-electron reduced species [Fe(8)(μ(4)-O)(4)(μ-4-Cl-pyrazolato)(12)Cl(4)](-) are consistent with a redox event that is localized within the cubane core. 相似文献
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Heisenberg’s explanation of how two coupled oscillators exchange energy represented a dramatic success for his new matrix
mechanics. As matrix mechanics transmuted into wave mechanics, resulting in what Heisenberg himself described as “…an extraordinary
broadening and enrichment of the formalism of the quantum theory”, the term resonance also experienced a corresponding evolution.
Heitler and London’s seminal application of wave mechanics to explain the quantum origins of the covalent bond, combined with
Pauling’s characterization of the effect, introduced resonance into the chemical lexicon. As the Valence Bond approach gave
way to a soon-to-be dominant Molecular Orbital method, our understanding of the term resonance, as it might apply to our understanding
the chemical bond, has also changed. 相似文献
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Michael J. S. Dewar Eamonn F. Healy James J. P. Stewart 《Journal of computational chemistry》1984,5(4):358-362
MNDO has been parametrized for iodine. Since d atomic orbitals (AOS ) are not included, the calculations are restricted to II. Heats of formation, molecular geometries, ionization energies, and dipole moments are reproduced with useful accuracy. 相似文献
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The Role of the Detergent Micelle in Preserving the Structure of Membrane Proteins in the Gas Phase 下载免费PDF全文
Eamonn Reading Idlir Liko Dr. Timothy M. Allison Prof. Justin L. P. Benesch Prof. Arthur Laganowsky Prof. Carol V. Robinson 《Angewandte Chemie (International ed. in English)》2015,54(15):4577-4581
Despite the growing importance of the mass spectrometry of membrane proteins, it is not known how their transfer from solution into vacuum affects their stability and structure. To address this we have carried out a systematic investigation of ten membrane proteins solubilized in different detergents and used mass spectrometry to gain physicochemical insight into the mechanism of their ionization and desolvation. We show that the chemical properties of the detergents mediate the charge state, both during ionization and detergent removal. Using ion mobility mass spectrometry, we monitor the conformations of membrane proteins and show how the surface charge density dictates the stability of folded states. We conclude that the gas‐phase stability of membrane proteins is increased when a greater proportion of their surface is lipophilic and is consequently protected by the physical presence of the micelle. 相似文献
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Hakl József de Châtel F. Péter Mészáros Sándor Vad Kálmán Klencsár Zoltán Németh Zoltán Kuzmann Ernő Homonnay Zoltán Vértes Attila Simopoulos Athanassios Devlin Eamonn Aoki Yoshitaka Konno Hidetaka De Subodh Kumar 《Solid State Sciences》2009,11(4):852-860
Transport and magnetic properties of LaCoO3-based compounds, doped with 20% Sr and 2.5, 5, 10, 15, 20 and 30% Fe, were investigated by means of magnetization, resistivity and magnetoresistance measurements as well as by 57Fe Mössbauer spectroscopy. While the temperature dependence of the dc and ac magnetic susceptibilities reveals the presence of magnetic phase separation accompanied by spin-glass and cluster-glass behavior, the electrical resistivity and magnetoresistance characteristics indicate that the mesoscopic structure of the present compounds is rather well described as consisting of ferromagnetic, metallic grains embedded in an insulating matrix. The effect of the partial Co → Fe substitution on the bulk magnetic and transport properties, as well as on the local state of Co and Fe ions is discussed. 相似文献