Hydrogen Bond and Proton Transport in Acid鈥揃ase Complexes and Amphoteric Molecules by Density Functional Theory Calculations and 1H and 31P Nuclear Magnetic Resonance Spectroscop

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• 作者：Liqing Xie ; Huiting Liu ; Shuaiyuan Han ; Baohua Yue ; Liuming Yan
• 刊名：Journal of Physical Chemistry B
• 出版年：2013
• 出版时间：December 19, 2013
• 年：2013
• 卷：117
• 期：50
• 页码：16345-16355
• 全文大小：603K
• 年卷期：v.117,no.50(December 19, 2013)
• ISSN：1520-5207

文摘

Intermolecular and intramolecular hydrogen bond (H-bond) and proton transport in acid鈥揵ase complexes and amphoteric molecules consisting of phosphonic acid groups and nitrogenous heterocyclic rings are investigated by density functional theory calculations and ¹H NMR and ³¹P NMR spectroscopy. It is concluded that a phosphonic acid group can act both as H-bond donor and H-bond acceptor, while an imine nitrogen atom can only act as H-bond acceptor and an amine group as H-bond donor. And the intramolecular H-bond is weaker than the intermolecular H-bond attributing to configurational restriction. In addition, the strongest H-bond interaction is observed between a phosphonic acid and a 1H-indazole because of the formation of double H-bonds. The ¹H NMR and ³¹P NMR chemical shifts for the acid鈥揵ase complexes are consistent with the density functional theory calculations. From the ¹H NMR chemical shifts, fast proton exchange is observed between a phosphonic acid and 1H-benzimidazole or 1H-indazole. Finally, it is proposed that polymeric material tethered with 1H-benzimidazole or 1H-indazole rings is a favorable component for high-temperature proton exchange membranes based on acid鈥揵ase complexes or acid鈥揵ase amphoteric molecules.