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求助C-H...C作用的文献
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求碳碳作用算做氢键或弱作用的文献。 谢谢 |
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2楼2009-06-30 14:38:55
xi2004
至尊木虫 (职业作家)
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navypang(金币+10,VIP+0):谢谢，xi2004，感谢你多次的帮助 6-30 15:03
paopaomeng(金币+1,VIP+0):谢谢交流 7-1 11:33
navypang(金币+10,VIP+0):谢谢，xi2004，感谢你多次的帮助 6-30 15:03
paopaomeng(金币+1,VIP+0):谢谢交流 7-1 11:33
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xixi, 来赚点钱 Titre du document / Document title Intramolecular C-H...Ccarbene hydrogen bonds and competing interactions in monoprotonated tripodal carbenes Auteur(s) / Author(s) HOWARD Sian T. ; ABERNETHY Colin D. ; Résumé / Abstract The anionic tripodal N-heterocyclic carbene (C3N2H3)3BH- first prepared by Fehlhammer, together with three neutral variants, (C3N2H3)3CH, (C3N2H3)3P, and (C3N2H3)3SiH, have been studied using quantum chemical methods. Isodesmic reactions are used to deduce that the phosphine-bridgehead species in particular has a large-resonance stabilization energy. All the podands undergo substantial conformational change on excitation to the lowest triplet electronic state, with effective localization of the excitation on one of the heterocyclic rings, dearomatizing it. On monoprotonation of the ground states, three of these species display intramolecular C-H...Ccarbene hydrogen bonding: The nature and strength of these interactions is explored using model (intermolecularly hydrogen-bonded) complexes, isodesmic reactions, and GIAO calculations of chemical shifts. One surprising result is that C-H...Ccarbenehydrogen bonds involving ethenic hydrogens can be almost as strong as those involving the imidazolium proton (first identified by Arduengo). The case of the monoprotonated carbon bridgehead species is in particular intriguing. It is stabilized by a competitive CcarbeneC...N interaction of sufficient strength to override the C-H...Ccarbenebonding motif observed in the other structures. Revue / Journal Title Journal of computational chemistry ISSN 0192-8651 CODEN JCCHDD Source / Source 2004, vol. 25, no5, pp. 649-659 [11 page(s) (article)] Langue / Language Anglais Editeur / Publisher Wiley, New York, ETATS-UNIS (1980) (Revue) Localisation / Location INIST-CNRS, Cote INIST : 18378, 35400011358406.0050 |
3楼2009-06-30 14:55:16
xi2004
至尊木虫 (职业作家)
- CMEI: 10
- 应助: 125 (高中生)
- 金币: 16769.9
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- 帖子: 4161
- 在线: 436.9小时
- 虫号: 354550
- 注册: 2007-04-24
- 专业: 结构化学
4楼2009-06-30 14:56:41