Hydrogen bonding of hydrates of double acetic acid molecules.
Hydrogen bonding of hydrates of double acetic acid molecules.
复制标题
DOI：
10.1021/jp902634h
复制
发表时间：
2009-06
期刊：
影响因子：
--
通讯作者：
L. Pu;Yueming Sun;Zhibing Zhang
中科院分区：
文献类型：
--
作者：
L. Pu;Yueming Sun;Zhibing Zhang
在化学工业中，醋酸从HAc/H（2）O体系中分离时，往往受到氢键的影响。采用从头算分子动力学（AIMD）和量子化学计算（QCC）两种第一性原理方法，对双乙酸（HAc）分子的各种水合物的氢键进行了研究.根据AIMD模拟，揭示了乙酸头环的分布，并表明有利的结构倾向于乙酸水合物而不是HAc环状二聚体。分别涉及单和双HAc分子的6-和10-元头环似乎是主导结构。根据QCC，最稳定的结构被发现是每个组中具有最大的头对环的构象。环的能量学表明，环的稳定性随着环尺寸的增加而增加（9元环除外），并且10元环是最稳定的。静态QCC结果所暗示的环结构的相对稳定性与AIMD模拟的统计环分布一致。
In the chemical industry, the separation of the acetic acid from the HAc/H(2)O system is always influenced by the hydrogen bonding. In the present work, an investigation on the hydrogen bonding of various hydrates of double acetic acid (HAc) molecules is carried out with two first-principle methods including ab initio molecular dynamics (AIMD) simulation and quantum chemical calculations (QCC). From the AIMD simulation, the distribution of the head-on rings of acetic acid is revealed and shows that the favorable structures tend to be the acetic acid hydrates rather than the HAc cyclic dimer. The 6- and 10-membered head-on rings involving single and double HAc molecules, respectively, appear to be the dominant structures. According to the QCC, the most stable structure is found to be the conformer with the biggest head-on ring in each group. The energetics of the rings indicates that the stability of the ring increases with increased ring size (with the exception of the 9-membered ring), and the 10-membered ring is the most stable. The relative stability of the ring structures implied by the static QCC result is in good agreement with the statistical ring distribution of the AIMD simulation.