Computational Estimates of Thermochemistry and pKa Values of Cyclopropenyl Imine Superbases

被引:19
作者
Ciftcioglu, Gokcen A. [1 ]
Trindle, Carl [2 ]
机构
[1] Marmara Univ, Deparment Chem Eng, TR-34722 Istanbul, Turkey
[2] Univ Virginia, Dept Chem, Charlottesville, VA 22904 USA
关键词
superbases; proton affinities; basicity; density functional theory; DENSITY FUNCTIONALS; PROTON AFFINITIES; GAS-PHASE; HEAT;
D O I
10.1002/qua.24576
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The thermochemical properties of superbase species derived from cyclopropeneimine are estimated by computations on systems of isodesmic reactions. Proton affinities, gas phase basicities, and pK(a) values are well represented by computations incorporating G4 and CBS-QB3 schemes augmented for large systems by DFT calculations with functionals M06-2X and B97DX in the cc-pVTZ Dunning basis. Our calculations show that relative base strengths in gas are enhanced by alkyl substitution, either by methyl groups or larger species. For acetonitrile solution, alkyl substitution seems to weaken the base. (c) 2013 Wiley Periodicals, Inc.
引用
收藏
页码:392 / 399
页数:8
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