Deuterium Isotope Effects on Acid-Base Equilibrium of Organic Compounds.
Deuterium Isotope Effects on Acid-Base Equilibrium of Organic Compounds.
复制标题
氘同位素对有机化合物酸碱平衡的影响
DOI：
10.3390/molecules26247687
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发表时间：
2021-12-20
期刊：
影响因子：
--
通讯作者：
Gao J
中科院分区：
文献类型：
--
作者：
Liu M;Gao J
采用路径积分和自由能微扰模拟相结合的方法研究了氘同位素对酸碱平衡的影响。为了理解的线性自由能关系的起源对，我们研究了两个理论模型计算氘同位素效应。在模型1中，通过用氘取代可滴定质子，仅包括酸本身在水中的固有同位素交换效应。在这里，主要贡献是由于两种同位素之间零点能量的差异。在模型2中，考虑了介质同位素效应，确定了溶质-溶剂氢键复合物中D_2O取代H_2O的自由能变化。虽然从模型1的平均变化被认为是在合理的协议与实验平均结果，溶剂同位素效应的依赖性是不存在的。模型2中考虑了介质效应，得到了线性自由能关系，主要因素是阴离子-水络合物中的溶剂同位素效应。本研究强调了固有同位素交换效应和介质溶剂同位素效应的重要作用。
Deuterium isotope effects on acid–base equilibrium have been investigated using a combined path integral and free-energy perturbation simulation method. To understand the origin of the linear free-energy relationship of versus , we examined two theoretical models for computing the deuterium isotope effects. In Model 1, only the intrinsic isotope exchange effect of the acid itself in water was included by replacing the titratable protons with deuterons. Here, the dominant contribution is due to the difference in zero-point energy between the two isotopologues. In Model 2, the medium isotope effects are considered, in which the free energy change as a result of replacing H2O by D2O in solute–solvent hydrogen-bonding complexes is determined. Although the average change from Model 1 was found to be in reasonable agreement with the experimental average result, the dependence of the solvent isotope effects is absent. A linear free-energy relationship is obtained by including the medium effect in Model 2, and the main factor is due to solvent isotope effects in the anion–water complexes. The present study highlights the significant roles of both the intrinsic isotope exchange effect and the medium solvent isotope effect.
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用于计算溶液中有机物质的平衡同位素分馏因子的双QM和MM方法。
DOI：
10.3390/molecules23102644
发表时间：
2018-10-15
期刊：
Molecules (Basel, Switzerland)
影响因子：
--
作者：
Liu M;Youmans KN;Gao J
通讯作者：
Gao J
影响因子：
--
作者：
Gao J
通讯作者：
Gao J
DOI：
10.1073/pnas.1704786114
发表时间：
2017-06-20
影响因子：
11.1
作者：
Harijan, Rajesh K.;Zoi, Ioanna;Schramm, Vern L.
通讯作者：
Schramm, Vern L.
影响因子：
1.1
作者：
BOLTON, PD;HALL, FM;KUDRYNSK.J
通讯作者：
KUDRYNSK.J
影响因子：
2.9
作者：
Fan Y;Cembran A;Ma S;Gao J
通讯作者：
Gao J