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61.
Protonated and methylated dimethyl sulfoxide cations and dications. DFT/GIAO-MP2 NMR studies and comparison with experimental data 总被引:1,自引:0,他引:1
Energies, electronic structures, and thermodynamics of protonated and methylated dimethyl sulfoxide (DMSO) cations and dications were calculated using the density functional theory (DFT) method. The O-protonated structure 2 was found to be 37.0 kcal/mol more stable than the S-protonated 3. For diprotonated DMSO dication, the O, O-diprotonated form 6 was found to be the global minimum, more stable by 20.8 kcal/mol than O,S-diprotonated 7. Interestingly, for dimethylated DMSO dication, O,O-dimethylated 11 and O,S-dimethylated 12 are isoenergetic. (13)C, (17)O, and (33)S NMR chemical shifts of the cations and dications were calculated using the GIAO-MP2 method and compared with the available experimental data. 相似文献
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Cover Picture: Long‐Lived Trifluoromethanide Anion: A Key Intermediate in Nucleophilic Trifluoromethylations (Angew. Chem. Int. Ed. 43/2014)
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Alina Marieta Simion Takashi Arimura Akira Miyazawa G. K. Surya Prakash George A. Olah 《合成通讯》2013,43(16):2859-2865
Secondary and tertiary amines can be easily obtained from primary and secondary amines, respectively, in completely aqueous media, in the presence of a bicatalytic system formed of cheap commercial aluminum (Al) powder and 5% rhodium (Rh) or ruthenium (Ru) deposed on charcoal. 相似文献
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[reaction: see text] Addition of a trifluoromethyl group into aldimines was accomplished using (trifluoromethyl)trimethylsilane with tetraalkylammonium fluorides as initiators, and the resulting adducts were converted to difluoromethylated imines in the presence of excess fluoride. The imines were reduced to difluoromethylated amines using sodium borohydride. 相似文献
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Tri- and tetraprotonated ethane (C2H9(3+) and C2H10(4+)) containing five- and six-coordinate carbons
Triprotonated ethane (C(2)H(9)(3+)) 4 and tetraprotonated ethane (C(2)H(10)(4+)) 6 were found by ab initio MP2/cc-pVTZ calculations as viable energy minima. Their structure has three and four two-electron three-center (2e-3c) bonds, respectively. In contrast, calculations showed no minimum-energy structure on the potential energy surface of pentaprotonated ethane (C(2)H(11)(5+)). Charge-charge repulsion may approach its limit in this case. Sufficient stabilization of polycations by Schmidbaur-type auration with (C(6)H(5))(3)PAu, an isolobal analogue of H(+), should be possible for the preparation of the polyaurate derivatives of poly protonated ethane allowing their structural study. 相似文献
70.
LetX andY beT
1 topological spaces andG(X, Y) the space of all functions with closed graph. Conditions under which the Fell topology and the weak Fell topology coincide
onG(X,Y) are given. Relations between the convergence in the Fell topologyτF, Kuratowski and continuous convergence are studied too. Characterizations of a topological spaceX by separation axioms of (G(X, R), τF) and topological properties of (G(X, R), τF) are investigated. 相似文献