Calculations of pKa of superacids in 1,2-dichloroethane.
Calculations of pKa of superacids in 1,2-dichloroethane.
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DOI：
10.1021/jp202434p
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发表时间：
2011-05
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影响因子：
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通讯作者：
A. Trummal;A. Rummel;É. Lippmaa;I. Koppel;I. Koppel
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作者：
A. Trummal;A. Rummel;É. Lippmaa;I. Koppel;I. Koppel
采用SMD和cosmos - rs连续溶剂化模型对1,2-二氯乙烷（DCE）中CH和NH超强酸的酸度进行了计算。将计算结果与各自的实验pK(a)值进行比较，发现SMD/M05-2X/6-31G*方法的平均无符号误差（MUE）为0.5 pK(a)单位，回归线斜率为0.915。类似的SMD/B3LYP/6-31G*方法稍不成功。M05-2X和B3LYP泛函的R(2)值分别为0.990和0.984，证实了整个数据集的强相关性。COSMO-RS方法提供的线性回归线斜率值与SMD方法的相应值相似，但DCE溶液中计算pK(a)值与实验pK(a)值具有较松散的相关性(R（2) = 0.823, MUE = 1.7 pK(a)单位）。
Acidity calculations for some CH and NH superacids in 1,2-dichloroethane (DCE) were carried out using SMD and COSMO-RS continuum solvation models. After comparing the results of calculations with respective experimental pK(a) values it was found that the performance of SMD/M05-2X/6-31G* method is characterized by the mean unsigned error (MUE) of 0.5 pK(a) units and the slope of regression line of 0.915. The similar SMD/B3LYP/6-31G* approach was slightly less successful. The strong correlation over entire data set is confirmed by R(2) values of 0.990 and 0.984 for M05-2X and B3LYP functionals, respectively. The COSMO-RS method, while providing the value of the linear regression line slope similar to the corresponding values from SMD approach, characterized by rather loose correlation (R(2) = 0.823, MUE = 1.7 pK(a) units) between calculated and experimental pK(a) values in DCE solution.