Stabilization of Carboxylate Anion with a NH···O Hydrogen Bond: Facilitation of the Deprotonation of Carboxylic Acid by the Neighboring Amide NH Groups
Stabilization of Carboxylate Anion with a NH···O Hydrogen Bond: Facilitation of the Deprotonation of Carboxylic Acid by the Neighboring Amide NH Groups
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NH·O 氢键稳定羧酸根阴离子：邻近酰胺 NH 基团促进羧酸去质子化
DOI：
10.1246/bcsj.77.321
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发表时间：
2004
影响因子：
4
通讯作者：
N. Ueyama
中科院分区：
文献类型：
--
作者：
A. Onoda;Yusuke Yamada;Jiro Takeda;Yoshiki Nakayama;T. Okamura;Mototsugu Doi;Hitoshi Yamamoto;N. Ueyama
羧酸、2,6-(t-BuCONH) 2 C 6 H 3 COOH (1) 和 2-t-BuCONH-6-MeC 6 H 3 COOH (2)、羧酸盐、[NEt 4 ][2,6-(t-BuCONH) 2 C 6 H 3 COO] (3) 和混合络合物 [N(n-Pr) 的 NH...O 氢键的形成4][H{2,6-(t-BuCONH) 2 C 6 H 3 (COO)} 2 ](4)，通过X射线结构分析确定。固态和溶液中的 1 H NMR 和 IR 光谱。酰胺NH基团在NH与O=C基团之间形成弱的分子内氢键，而在羧酸状态下不形成NH...OH氢键。羧酸根阴离子 3 在 NH...O -（阴离子）之间形成强的分子内部分共价氢键。 NH...O 氢键的强度在低介电常数的溶液中也得以维持。在胶束溶液中测量的 1 和 2 的 pKa 值表明，去质子化的重要触发因素之一是 OH 基团的氧原子与酰胺 NH 的直接相互作用。
The formation of the NH...O hydrogen bonds of carboxylic acids, 2,6-(t-BuCONH) 2 C 6 H 3 COOH (1) and 2-t-BuCONH-6-MeC 6 H 3 COOH (2), carboxylate, [NEt 4 ][2,6-(t-BuCONH) 2 C 6 H 3 COO] (3), and a mixed complex, [N(n-Pr) 4 ][H{2,6-(t-BuCONH) 2 C 6 H 3 (COO)} 2 ] (4), were determined by X-ray structure analysis. 1 H NMR, and IR spectroscopy, both in the solid state and in solution. The amide NH group forms weak intramolecular hydrogen bond between the NH and O=C group, and no NH...OH hydrogen bond is formed in the carboxylic acid state. Carboxylate anion 3 forms a strong, intramolecular, partially-covalent hydrogen bond between NH...O - (anion). The strength of the NH...O hydrogen bonds is also maintained in a solution having a low dielectric constant. The pK a values for 1 and 2, measured in a micellar solution, indicated that one of the important triggers for deprotonation is a direct interaction toward the oxygen atom of the OH group with the amide NHs.
影响因子：
2.9
作者：
WARSHEL, A
通讯作者：
WARSHEL, A
能源方面的考虑表明，低势垒氢键并不比普通氢键具有催化优势。
DOI：
10.1073/pnas.93.24.13665
发表时间：
1996
影响因子：
11.1
作者：
Warshel,A;Papazyan,A
通讯作者：
Papazyan,A
影响因子：
2.9
作者：
WARSHEL, A;NARAYSZABO, G;HWANG, JK
通讯作者：
HWANG, JK