Substituent effects on the conformational stability of allyl fluorides

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	Substituent effects on the conformational stability of allyl fluorides
	Qiu, Y. G. ; Han, D. X. ; Han DX(韩大雄)
刊名	http://dx.doi.org/10.1002/poc.1777
	2011-05
关键词	RARE-GAS SOLUTIONS AB-INITIO CALCULATIONS FT-IR SPECTRA STRUCTURAL PARAMETERS VIBRATIONAL ASSIGNMENT DENSITY FUNCTIONALS INTERNAL-ROTATION STERIC REPULSION INFRARED-SPECTRA 3-FLUOROPROPENE
英文摘要	Hanshan Normal University; Natural Science Foundation of China [40706043, 40976050]; By the B3P86/6-311G(3d,2p) method, remote substituent effects on trans-YCH=CHCH(2)F were investigated by examining their conformational stabilities, molecular geometries, and stereoelectronic interactions in this paper. The cis conformer is favored for Y=H, Cl, Me, Vinyl, CF(3), CN, CHO, and NO(2), whereas the gauche is favored for Y=OMe, OH. A correlation of Delta H with the substituent constants sigma(+)(Y) shows that the increasing electron-withdrawing ability of the substituent Y increases the relative stability of the cis conformer. It was found that the substituent effect on the molecule stabilization energies (relative to CH(2)=CHCH(2)F) is more significant in the gauche conformers than in the cis conformers. In agreement, molecular structures of the gauche conformers were also observed to vary more significantly with the substitution than those of the cis conformers. By the second-order perturbation energy (E(2)) in NBO analysis, it was found that the total C(2)-C(3) vicinal hyperconjugation is determinant in the enthalpy difference and consequently controls the conformational stability. Further analysis shows that the substituent effect on the C(2)-C(3) vicinal hyperconjugations is much higher in the gauche conformers than in the cis conformers. The highly sensitive pi(C=C)-> sigma*(C-F) interaction to the substitution in the gauche conformers, is the leading factor in variation of molecular stability and geometry. Copyright (C) 2010 John Wiley & Sons, Ltd.
语种	英语
内容类型	期刊论文
源URL	[http://dspace.xmu.edu.cn/handle/2288/71518]
专题	医学院－已发表论文
推荐引用方式 GB/T 7714	Qiu, Y. G.,Han, D. X.,Han DX. Substituent effects on the conformational stability of allyl fluorides[J]. http://dx.doi.org/10.1002/poc.1777,2011.
APA	Qiu, Y. G.,Han, D. X.,&韩大雄.(2011).Substituent effects on the conformational stability of allyl fluorides.http://dx.doi.org/10.1002/poc.1777.
MLA	Qiu, Y. G.,et al."Substituent effects on the conformational stability of allyl fluorides".http://dx.doi.org/10.1002/poc.1777 (2011).