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201.
Akola J Walter M Whetten RL Häkkinen H Grönbeck H 《Journal of the American Chemical Society》2008,130(12):3756-3757
Density functional theory is used to explore the structure of Au25(RS)18. The preferred structure consists of an icosahedral Au13 core protected by 6 RS-Au-RS-Au-RS units. The enhanced stability of the structure as an anion is found to originate from closure of an eight-electron shell for delocalized Au(6s) electrons. The evaluated XRD pattern and optical spectra are in good agreement with experimental data. 相似文献
202.
The dissociation dynamics of the excited Xe(3) (+) molecular ion through the Pi(12)(u) and Pi(12)(g) conical intersection was interrogated by computational simulation in which no adjustable parameters were used. The electronic ground and excited state potential energy surfaces were generated by the diatomics-in-molecules method, and the Ehrenfest mean-field and Tully surface-hopping approaches treated the nonadiabatic interactions. Reproduction of the experimental spectrum of the symmetric photofragmentation as a function of excitation energy was obtained within the region of interest (2.5-3.75 eV), with the exception of a 0.25 eV width on the red side of the spectral apex. Good agreement was obtained with the experimental dissociated photofragment kinetic energy spectra. It was determined that the greatest contribution to the nonadiabatic coupling between the two states originated from the bending vibrational mode of the molecule in the Sigma(12)(u), ground electronic state before excitation. 相似文献
203.
Dr. M. Rita Correro Dr. Negar Moridi Hansjörg Schützinger Sabine Sykora Erik M. Ammann E. Henrik Peters Dr. Yves Dudal Prof. Dr. Philippe F.‐X. Corvini Prof. Dr. Patrick Shahgaldian 《Angewandte Chemie (International ed. in English)》2016,55(21):6285-6289
The fragile nature of most enzymes is a major hindrance to their use in industrial processes. Herein, we describe a synthetic chemical strategy to produce hybrid organic/inorganic nanobiocatalysts; it exploits the self‐assembly of silane building blocks at the surface of enzymes to grow an organosilica layer, of controlled thickness, that fully shields the enzyme. Remarkably, the enzyme triggers a rearrangement of this organosilica layer into a significantly soft structure. We demonstrate that this change in stiffness correlates with the biocatalytic turnover rate, and that the organosilica layer shields the enzyme in a soft environment with a markedly enhanced resistance to denaturing stresses. 相似文献
204.
We study the algebra \({{\mathrm{{\mathcal {MD}}}}}\) of generating functions for multiple divisor sums and its connections to multiple zeta values. The generating functions for multiple divisor sums are formal power series in q with coefficients in \({\mathbb {Q}}\) arising from the calculation of the Fourier expansion of multiple Eisenstein series. We show that the algebra \({{\mathrm{{\mathcal {MD}}}}}\) is a filtered algebra equipped with a derivation and use this derivation to prove linear relations in \({{\mathrm{{\mathcal {MD}}}}}\). The (quasi-)modular forms for the full modular group \({{\mathrm{SL}}}_2({\mathbb {Z}})\) constitute a subalgebra of \({{\mathrm{{\mathcal {MD}}}}}\), and this also yields linear relations in \({{\mathrm{{\mathcal {MD}}}}}\). Generating functions of multiple divisor sums can be seen as a q-analogue of multiple zeta values. Studying a certain map from this algebra into the real numbers we will derive a new explanation for relations between multiple zeta values, including those of length 2, coming from modular forms. 相似文献
205.
Henrik Stetkær 《Aequationes Mathematicae》2016,90(2):407-409
If \({f, g : G \to \mathbb{C}}\), f ≠ 0, is a solution of Wilson’s functional equation on a group G, then g is a d’Alembert function. 相似文献
206.
Hsieh S Miller BJ Södergren AH Kjaergaard HG 《The journal of physical chemistry. A》2007,111(25):5415-5421
We have recorded vapor-phase photoacoustic spectra of cyclopropane, ethylene oxide, and ethylene sulfide in the third, fourth, and fifth CH-stretching overtone regions. We have used a harmonically coupled anharmonic oscillator local mode model to facilitate analysis of the spectra. Fermi resonance between the CH-stretching and HCH-bending vibrations is essential to explain the observed wide and multistructured CH-stretching overtone bands. A number of weak combination bands can account for the remaining experimental features observed to the blue of the CH-stretching regions. We have reassigned the fundamental spectra of these three-membered rings. 相似文献
207.
Hattori K Ishiuchi S Fujii M Howard DL Kjaergaard HG 《The journal of physical chemistry. A》2007,111(27):6028-6033
We have measured the OH-stretching fundamental and overtone spectra of resorcinol and hydroquinone in a supersonic jet using nonresonant ionization detected infrared/near-infrared spectroscopy. Anharmonic oscillator local mode calculations of the OH-stretching frequencies and intensities and Boltzmann populations of the stable rotamers have been calculated at the B3LYP/6-311++G(3df,2pd) level to help interpret the observed spectra. Resorcinol has three stable rotamers and in the recorded second and third OH-stretching overtone spectra there is evidence of two distinguishable rotamers. Hydroquinone has two stable rotamers; however, the OH-stretching oscillators of each rotamer are so similar in nature that even up to the fourth OH-stretching overtone the transitions coincide. These results place a limit on the ability of the jet-cooled overtone spectroscopy technique to distinguish between rotamers. 相似文献
208.
Bromfield KM Gradén H Hagberg DP Olsson T Kann N 《Chemical communications (Cambridge, England)》2007,(30):3183-3185
A novel synthetic route towards oseltamivir, an influenza neuraminidase inhibitor, has been achieved employing a cationic iron carbonyl complex, providing an alternate pathway with the potential to access diverse analogues. 相似文献
209.
Sundén H Ibrahem I Zhao GL Eriksson L Córdova A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(2):574-581
The first direct organocatalytic asymmetric domino oxa-Michael/aldol condensation reaction is presented. The unprecedentedly simple, chiral, pyrrolidine-catalyzed asymmetric domino reactions between salicylic aldehyde derivatives and alpha,beta-unsaturated aldehydes proceed with high chemo- and enantioselectivities to give the corresponding chromene-3-carbaldehyde derivatives in high yields and with ee values of 83-98%. 相似文献
210.
We report second order Moller-Plesset (MP2) and MP2-F12 total energies on He, Ne, Ar, H(2)O, CH(4), C(2)H(2), C(2)H(4), and C(6)H(6), using the correlation consistent basis sets, aug-cc-pVXZ (X=D-7). Basis set extrapolation techniques are applied to the MP2 and MP2-F12/B methods. The performance of the methods is tested in the calculations of the atoms, He, Ne, and Ar. It is indicated that the two-point extrapolation of MP2-F12/B with the basis sets (X=5,6) is the most reliable. Similar accuracy is obtained using two-point extrapolated conventional MP2 with the basis sets (X=6,7). For the molecules investigated the valence MP2 correlation energy is estimated within 1 mE(h). 相似文献