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991.
Dr. Kenward King Ho Vong Dr. Satoshi Maeda Dr. Katsunori Tanaka 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(52):18865-18872
Alkyl esters, such as propargyl esters, typically lack the electron‐withdrawing inductive effects needed to participate in nucleophilic acyl substitution reactions. Herein, we report an unusual observation in which glycine propargyl ester derivatives displayed selective, base‐independent reactivity towards linear alkylamines under mild, metal‐free conditions. Through global reaction route mapping (GRRM) modeling calculations, it is predicted that these observations may be governed by factors related to hydrogen‐bonding and intermolecular interactions, rather than electron‐withdrawing inductive effects. Based on this concept of propargyl‐assisted selective amidation, a direct application was made to develop a novel site‐specific C‐terminal glycine peptide bioconjugation technique as a proof‐of‐concept, which relies upon the selective reactivity of glycine propargyl esters over that of aspartate and glutamate side‐chain‐linked propargyl esters. 相似文献
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Oxalyl chloridefluoride (COCl)(COF) exhibits moderately strong discrete absorption in the 3050–3540Å region. The band spectrum has been analyzed as an allowed electronic transition of the planar trans molecule. The most active vibrations are the carbonyl stretching modes ν1′ and ν2′ and the in-plane bending mode ν9. Various other fundamental frequencies in the combining electronic states have been identified. The 000 band is at 28 724.5 cm−1; partial rotational analysis confirms that this band is type C. The appearance of “line” structure in the wings of the band is discussed and an explanation offered. The vibrational and rotational analyses confirm that the transition is
under the Cs point group, as expected for a singlet-singlet n → π* type of excitation. 相似文献
995.
M.A. King H.W. Kroto J.F. Nixon D. Klapstein J.P. Maier O. Marthaler 《Chemical physics letters》1981,82(3):543-545
The electron impact excited Ã2Σ+ → X?+Π emission spectra of HCP+ and DCP+ have been observed. The spin-orbit split 0-0 band has maxima at 593.7 and 599.0 nm for HCP+ and 593.6 and 598.8 nm for DCP+. Short progressions in the V3(CP) vibration are observed. a0, v3 and the upper-state lifetime are determined. 相似文献
996.
Christopher King 《Letters in Mathematical Physics》1992,25(1):17-28
We compute the scattering operator for a simplified model of an atom interacting a with a quantized field. The field is restricted to the vacuum and one-particle sectors, and the atom has only two states. We also solve the inverse scattering problem for the same model. The methods used rely on the particular form of the interaction, which is chosen to mimic the interaction between radiation and matter.This work was partially supported by NSF Grant DMS-8922941. 相似文献
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W.F. King 《Journal of sound and vibration》1977,54(3):361-378
The relative contributions of aerodynamic and wheel/rail noise to railway wayside noise levels are not well understood. Methods for predicting these contributions discussed in this paper include (i) an equation for turbulent boundary layer noise (the minimum wayside noise), (ii) an empirical formula for total aerodynamic noise based on airframe noise studies, and (iii) the Peters equation for wheel/rail interaction noise. Comparisons are made between predicted and measured noise levels for (i) a buoyant vehicle, (ii) the Linear Induction Motor Research Vehicle (LIMRV), and (iii) a magnetically levitated vehicle. Analysis of these results indicates that aerodynamic fluctuations could become the dominant source 3f wayside noise at train speeds of 240–280 km/h. This prognosis is for new high speed railway vehicles equipped with disc brakes and other innovations that reduce the wheel/rail noise contribution. 相似文献