Corrigendum to “SPEEK/epoxy resin composite membranes in situ polymerization for direct methanol fell cell usages” [J. Power Sources 165 (2007) 708–716]

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• 作者：Tiezhu Fu ; Chengji Zhao ; Shuangling Zhong ; Gang Zhang ; Ke Shao ; Haiqiu Zhang ; Jing Wang ; Hui Na
• 关键词：N-Trifluoromethylsulfonyl derivatives of azinanes ; Conformation ; Dynamic NMR ; Perlin effect ; DFT calculations
• 刊名：Journal of Power Sources
• 出版年：2008
• 出版时间：1 August 2008
• 年：2008
• 卷：182
• 期：2
• 页码：653
• 全文大小：67 K

文摘

The stereodynamic behaviour of 1-(trifluoromethylsulfonyl)piperidine rong>1rong>, 4-(trifluoromethylsulfonyl)morpholine rong>2rong>, 1,4-bis(trifluoromethylsulfonyl)piperazine rong>3rong> and 4-(trifluoromethylsulfonyl)thiomorpholine 1,1-dioxide rong>4rong> was studied by low-temperature ¹H, ¹³C and ¹⁹F NMR spectroscopies. In acetone solution, compounds rong>1rong>, rong>2rong> and rong>4rong> were found to exist as mixtures of two conformers in the ratio of 4:1, 4:1 and 8:1, respectively, differing by orientation of the CF₃ group with respect to the ring. Compound rong>3rong> exists as a mixture of three conformers in the ratio of 3:28:69 also differing by the orientation of the two CF₃ groups. Unlike the previously studied N-trifyl substituted 1,3,5-triheterocyclohexanes, the preferred conformers of compound rong>1rong> and of 1,4-diheterocyclohexanes rong>2rong>–rong>4rong> are those with the CF₃ group directed outward from the ring, which is caused by intramolecular interactions of the oxygen atoms of the CF₃SO₂N groups with the equatorial hydrogens in the -position. B3LYP/6-311+G(d,p) calculations of the energy, geometry and NMR parameters corroborate the experimental data. The calculated Perlin effects for all conformers of compounds rong>1rong>–rong>4rong> as well as those measured for the major conformers of compounds rong>3rong> and rong>4rong> were analyzed by the use of the NBO analysis.