Basicities of Strong Bases in Water: A Computational Study

被引：101

作者：

Kaupmees, Karl ^{[1
]}

Trummal, Aleksander ^{[2
]}

Leito, Ivo ^{[1
]}

机构：

[1] Univ Tartu, Inst Chem, EE-50411 Tartu, Estonia

[2] NICPB, EE-10143 Tallinn, Estonia

来源：

CROATICA CHEMICA ACTA | 2014年 / 87卷 / 04期

关键词：

superbases; quantum chemistry in solution; aqueous basicity; DBU; UNCHARGED AUXILIARY BASES; GAS-PHASE; COSMO-RS; ACCURATE PREDICTION; ORGANIC SUPERBASES; PROTON AFFINITIES; ACIDITY CONSTANTS; AQUEOUS-SOLUTION; ABSOLUTE PK(A); SOLVATION;

D O I：

10.5562/cca2472

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Aqueous pK(a) values of strong organic bases - DBU, TBD, MTBD, different phosphazene bases, etc were computed with CPCM. SMD and COSMO-RS approaches. Explicit solvent molecules were not used. Direct computations and computations with reference pK(a) values were used. The latter were of two types: (I) reliable experimental aqueous pK(a) value of a reference base with structure similar to the investigated base or (2) reliable experimental pK(a) value in acetonitrile of the investigated base itself. The correlations of experimental and computational values demonstrate that direct computations do not yield pK(a) predictions with useful accuracy: mean unsigned errors (MUE) of several pK(a) units were observed. Computations with reference bases lead to MUE below 1 pK(a) unit and are useful for predictions. Recommended aqueous pK(a) values are proposed for all investigated bases taking into account all available information: experimental pK(a) values in acetonitrile and water (if available), computational pKa values, common chemical knowledge.

引用

页码：385 / 395

页数：11

共 62 条

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