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1.
2.
Thomas B. Grimley 《Theoretical chemistry accounts》1987,72(5-6):475-484
A model for one-phonon thermal desorption is presented in which the structure of the substrate phonons, expressed as a projection on a surface atom of the phonon density of states, appears as a separate factor in the angle- and energy-resolved desorption rate. Desorption from both localized, and delocalized initioladatom states is considered. Under certain circumstances one can obtain the cosine-distribution of the equilibrium theory, but in general, the desorption flux from delocalized states deviates from the cosine law by being peaked away from the surface normal, whereas for localized initiol states, the flux is concentrated more in the normal direction. 相似文献
3.
Maynadié J Delavaux-Nicot B Lavabre D Donnadieu B Daran JC Sournia-Saquet A 《Inorganic chemistry》2004,43(6):2064-2077
[(C(5)H(5))Fe(C(5)H(4)COCH=CHC(6)H(4)NEt(2))] (1) has been electrochemically evaluated toward different cations in solution. Calcium sensing by this compound and its two new derivatives [(C(5)H(5))Fe(C(5)H(4)CO(CH=CH)(2)C(6)H(4)NMe(2))] (2) and [(C(5)H(5))Fe(C(5)H(4)CH=CHCOCH=CHC(6)H(4)NEt(2))] (3) that exhibit a conjugated link between the ferrocene unit and the nitrogen atom has been thoroughly examined. Compounds 2 and 3 have been structurally characterized by single-crystal X-ray diffraction studies. The three related protonated species [1H][BF(4)] (4), [2H][BF(4)] (5), and [3H][BF(4)] (6) have been isolated in a good yield. NMR experiments clearly established that calcium interaction occurs in the vicinity of the carbonyl group, and mass spectrometry studies confirmed that this interaction, which involves several ligand-Ca(2+) adducts, is complex. A combination of electrochemical and NMR experiments highlighted an original salt influence on the electrochemical calcium sensing result. 相似文献
4.
5.
Alain J.P. Alix 《Journal of Molecular Structure》1976,33(1):137-139
Microwave spectra of CH18 OCOOH, CHOC18 OOH, CHOCO18 OH, 13 CHOCOOH and CHO13 COOH are reported and have been used in combination with data on CHOCOOH and CHOCOOD to determine the molecular structure as r(C=O)ald. = 1.174 ± 0.006 Å, r(C=O)acid = 1.203 ±0.006 Å, r(C—O) = 1.313 ± 0.010 Å, r(C—C) = 1.535 ± 0.005 Å, r(O—H) = 0.948 ± 0.004 Å, r(C—H) = 1.104 ±0.010 Å, ald. = 123.7 ± 0.4<, 相似文献
6.
Maud Jenart Claude Niebel Jean-Yves Balandier Julie Leroy Alix Mignolet Sara Stas Antoine Van Vooren Jérôme Cornil Yves Henri Geerts 《Tetrahedron》2012,68(1):349-355
Two quaterthiophene-based dimers including an ethylene bridge have been designed and efficiently prepared; experimental and computational studies show a promising potential as semiconducting material with a charge transport of higher dimensionality compared to quaterthiophene. 相似文献
7.
T.B. Grimley 《Molecular physics》2013,111(3):329-336
A proof is given of the proposition that the intensity of the N.M.R. absorption line from a group of n equivalent protons is proportional to n. To do this, it has been necessary to satisfy the Pauli exclusion principle by classifying states according to the irreducible representations of the symmetric group. As far as spin is concerned, this classification is equivalent to one according to the value of I, the total spin. Degeneracy with respect to I, which would otherwise occur, is prohibited by the exclusion principle, and a correlation (not one-to-one) is established between I and the symmetries of the rotational states. 相似文献
8.
The resonance mechanism for positive and negative ionization of an atom reflected from a metal surface is treated in the time-dependent Hartree-Fock approximation assuming that the atom moves on its classical trajectory. A simple model is parameterized to describe 30–500 eV Na atoms reflected from tungsten, and the ionization probabilities are calculated by numerical integration of the equation of motion of the time evolution operator. Significant ionization can only occur if either the ionization level, or the affinity level of the atom crosses the Fermi level beyond the range of the atom-metal hopping interaction. On clean tungsten, the former situation applies, and the probability of positive ionization is nearly unity, and of negative ionization nearly zero. 相似文献
9.
A method for the calculation of the probability of neutralisation of an ion, which is scattered from the surface of a solid is presented. It assumes the ion to move along a classical trajectory and solves for the time evolution operator for the electronic system. For one electron Hamiltonians the solution can be carried out exactly. Results are presented for scattering from a semi-infinite linear chain. 相似文献
10.
Stimulated Raman spectroscopy is used to probe the photoexcitation dynamics of CO2-laser-excited SF6 in a molecular free-expansion jet. Time-dependent depletion of rotational levels in the ground state is observed by monitoring the ν1 Raman spectrum at various delay times after the CO2-laser excitation pulse. Optical Stark shifts are also seen, at short delay times, arising from resonances of the IR laser pulse with ν3 transitions from both ground and ν1 = 1 states. Molecules excited to the ν3 = 1 level are detected by scanning the ν1 + ν3 ? ν3 hot band. A direct determination of the anharmonicity X13 = ?2.910 ± 0.002 cm?1 is thus obtained. 相似文献