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61.
Winter B Weber R Hertel IV Faubel M Jungwirth P Brown EC Bradforth SE 《Journal of the American Chemical Society》2005,127(19):7203-7214
Photoelectron spectroscopy combined with the liquid microjet technique enables the direct probing of the electronic structure of aqueous solutions. We report measured and calculated lowest vertical electron binding energies of aqueous alkali cations and halide anions. In some cases, ejection from deeper electronic levels of the solute could be observed. Electron binding energies of a given aqueous ion are found to be independent of the counterion and the salt concentration. The experimental results are complemented by ab initio calculations, at the MP2 and CCSD(T) level, of the ionization energies of these prototype ions in the aqueous phase. The solvent effect was accounted for in the electronic structure calculations in two ways. An explicit inclusion of discrete water molecules using a set of snapshots from an equilibrium classical molecular dynamics simulations and a fractional charge representation of solvent molecules give good results for halide ions. The electron binding energies of alkali cations computed with this approach tend to be overestimated. On the other hand, the polarizable continuum model, which strictly provides adiabatic binding energies, performs well for the alkali cations but fails for the halides. Photon energies in the experiment were in the EUV region (typically 100 eV) for which the technique is probing the top layers of the liquid sample. Hence, the reported energies of aqueous ions are closely connected with both structures and chemical reactivity at the liquid interface, for example, in atmospheric aerosol particles, as well as fundamental bulk solvation properties. 相似文献
62.
The enthalpy change of the reaction at 298 K between Br2 (l) and Sn(c) in CS2 as solvent giving SnBr4 (s) has been determined by calorimetry to be (?374, 2±1.4) kJ·mol?1, [(?89.45±0.33) kcal·mol?1]. By the same method the heat of solution of SnBr4 (c) in CS2 has been found to be (11.9±0.3) kJ·mol?1, [(2.84±0.08) kcal·mol?1]. Combining these results, a value of (?386.1±1.5) kJ·mol?1, [(?92.3±0.4) kcal·mol?1] is derived for the standard heat of formation of SnBr4 (c). Substituting this figure in the thermochemical cycle hitherto used for calculating the heat of formation of SnBr4 (c) gives ?124.3 kcal·mol?1 for the standard heat of formation of SnCl4 (l), which is in reasonable agreement with a recent determination of this quantity8. 相似文献
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64.
Zusammenfassung Darstellung und Eigenschaften von Ammonium-, Kalium-, Silber- und Thalliumsalzen des Triselenimides und der Diimidotriselensäure werden beschrieben, Infrarot-Spektren sowieDebye-Scherrer-Diagramme einiger dieser erstmalig dargestellten Verbindungen werden zu ihrer Charakterisierung mitgeteilt.Mit 3 Abbildungen1. Mitt.:A. Engelbrecht undF. Clementi, Mh. Chem.92, 555 (1961). 相似文献
65.
Alfred Trautwein Yutaka Maeda Frank E. Harris Helmuth Formanek 《Theoretical chemistry accounts》1974,36(1):67-76
Experimental Mössbauer spectra of the Fe57-enriched CO complex of sperm whale myoglobin (MbCO) at T= 4.2 K with and without applied magnetic field (H⊥γ) were measured to derive the sign of the electric field gradient (EFG), the quadrupole splitting ΔE Q, and the isomer shift δ of the heme iron. We find a positive EFG, δE Q = 0.363 mm/sec, and δ + 0.266 mm/sec. Molecular orbital calculations were carried out to obtain theoretical estimates of EFG and ΔE Q for several steric arrangements of the CO ligand relative to the heme group. Our results are most consistent with the conclusion that the iron is situated in the heme plane, and that a bent geometry with a Fe-C-O angle of about 135 ° is more favorable than a more symmetric structure with a linear Fe-C-O geometry. 相似文献
66.
Zusammenfassung Beim Abbau von Paucin wird Brenzcatechin, Kaffeesäure und Putrescin erhalten. Daraus und aus spektroskopischen Befunden ergibt sich für das Paucin die Strukturformel3.
Mit 6 Abbildungen
Meinem Lehrer, Prof. Dr.H. Bretschneider, zum 65. Geburtstag gewidmet. 相似文献
The structure of Paucine
Paucine can be degradated to catechol, caffeic acid and putrescine. This together with spectroscopic data allows us to deduce formula3 for paucine.
Mit 6 Abbildungen
Meinem Lehrer, Prof. Dr.H. Bretschneider, zum 65. Geburtstag gewidmet. 相似文献
67.
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69.
Arisaka K Auerbach LB Axelrod S Belz J Biery KA Buchholz P Chapman MD Cousins RD Diwan MV Eckhause M Ginkel JF Guss C Hancock AD Heinson AP Highland VL Hoffmann GW Horvath J Irwin GM Joyce D Kaarsberg T Kane JR Kenney CJ Kettell SH Kinnison WW Knibbe P Konigsberg J Kuang Y Lang K Lee DM Margulies J Mathiazhagan C McFarlane WK McKee RJ Melese P Milner EC Molzon WR Ouimette DA Riley PJ Ritchie JL Rubin P Sanders GH Schwartz AJ Sivertz M Slater WE Urheim J Vulcan WF Wagner DL Welsh RE Whyley RJ 《Physical review letters》1993,71(24):3910-3913
70.