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Urata S Tsuzuki S Takada A Mikami M Uchimaru T Sekiya A 《Journal of computational chemistry》2004,25(3):447-459
The intermolecular interaction energy curves of CH(3)OCH(3)-CH(2)F(2), CF(3)OCH(3)-CH(2)F(2), CF(3)OCF(3)-CH(2)F(2), CH(3)OCH(3)-CHF(3), CF(3)OCH(3)-CHF(3), and CF(3)OCF(3)-CHF(3) complexes were calculated by the MP2 level ab initio molecular orbital method using the 6-311G** basis set augmented with diffuse polarization functions. We investigate the fluorine substitution effects of both methane and dimethyl ether on intermolecular interactions. In addition, orientation dependence of intermolecular interaction energies is also studied with utilizing eight types of orientations. Our analyses demonstrate that partial fluorinations of methane make electrostatic interaction dominant, and consequently enhance attractive interaction at several specific orientations. On the contrary, fluorine substitutions of dimethyl ether substantially decrease the electrostatic interaction between ether and CH(2)F(2) or CHF(3); thus, there is no such characteristic interaction between the C-H of fluorinated methane and ether oxygen of CF(3)OCF(3) as conventional hydrogen bonding, due to reduced polarity of fluorinated ether. The combination of different pairs of the electrostatic interaction is therefore responsible for the intermolecular interaction differences among the complexes investigated herein and also their orientations. 相似文献
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Theoretical studies on atmospheric chemistry of HFE‐347mcc3: reactions with OH radicals and Cl atoms
Bhupesh Kumar Mishra Makroni Lily Asit K. Chandra Ramesh Chandra Deka 《Journal of Physical Organic Chemistry》2014,27(10):811-817
Detailed theoretical investigation has been performed on the mechanism, kinetics and thermochemistry of the gas phase reactions of CF3CF2CF2OCH3 (HFE‐347mcc3) with OH radicals and Cl atoms using M06‐2X/6‐31 + G(d,p) level of theory. Reaction profiles are modeled including the formation of pre‐reactive and post‐reactive complexes at entrance and exit channels, respectively. Using group‐balanced isodesmic reactions, the standard enthalpies of formation for species are also reported. The calculated bond dissociation energy for C―H bond is in good agreement with previous data. The rate constants of the two reactions are determined for the first time in a wide temperature range of 250–1000 K. At 298 K, the calculated rate coefficients are in good agreement with the experimental results. The atmospheric life time of HFE‐347mcc3 is estimated to be 4.4 years. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Benson J. Jelier Dr. Jon L. Howell Prof. Craig D. Montgomery Prof. Daniel B. Leznoff Prof. Chadron M. Friesen 《Angewandte Chemie (International ed. in English)》2015,54(10):2945-2949
Hydrofluoroethers are shown to alkylate tertiary amines readily under solvent‐free conditions, affording valuable tetraalkylammonium perfluoroalkoxides bearing α‐fluorines. The reaction of RFCF2? OCH3 (RF=CF2CF3, CF2CF2CF3, and CF(CF3)2) with NR1R2R3 produces twenty new α‐perfluoroalkoxides, [(CH3)NR1R2R3][RFCF2O] under mild conditions. These α‐perfluoroalkoxides are easy to handle, thermally stable, and can be used for the perfluoroalkoxylation of benzyl bromides. 相似文献
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Urata S Tsuzuki S Mikami M Takada A Uchimaru T Sekiya A 《Journal of computational chemistry》2002,23(15):1472-1479
The intermolecular interaction energies of the CH3OCH3? CH4, CF3OCH3? CH4, and CF3OCF3? CH4 systems were calculated by ab initio molecular orbital method with the electron correlation correction at the second order Møller–Plesset perturbation (MP2) method. The interaction energies of 10 orientations of complexes were calculated for each system. The largest interaction energies calculated for the three systems are ?1.06, ?0.70, and ?0.80 kcal/mol, respectively. The inclusion of electron correlation increases the attraction significantly. It gains the attraction ?1.47, ?1.19, and ?1.27 kcal/mol, respectively. The dispersion interaction is found to be the major source of the attraction in these systems. In the CH3OCH3? CH4 system, the electrostatic interaction (?0.34 kcal/mol) increases the attraction substantially, while the electrostatic energies in the other systems are not large. Fluorine substitution of the ether decreases the electrostatic interaction, and therefore, decreases the attraction. In addition the orientation dependence of the interaction energy is decreased by the substitution. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1472–1479, 2002 相似文献
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