Substituent Effects on the Acidity of Weak Acids. 4. Anilinium Ions

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Title:Substituent Effects on the Acidity of Weak Acids. 4. Anilinium Ions
Creators:
Wiberg, Kenneth B.
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 69, 12, pp. 2183-2192
Uncontrolled Keywords:Protonation, <i>Ab initio</i> calculations, Isodesmic reactions, Ammonium salts, Gas phase acidity, Substituent effects

Abstract

The gas phase acidity of anilinium ions has been calculated at a number of theoretical levels from B3LYP/6-311++G** to MP2 and CCSD/6-311++G(2dp,2pd). The highest level calculations find anilinium ion and <i>p</i>-protonated aniline to have essentially the same energy, in agreement with experimental studies. They also give a proton affinity for aniline that is in very good agreement with the experimental value. The B3LYP and MP2 calculations are less successful, with B3LYP favoring <i>p</i>-protonation and MP2 favoring N-protonation for aniline. Despite this difficulty, the calculated effect of substituents on the proton affinities of <i>p</i>-substituted anilines that undergo N-protonation agreed well with the experimental data. The effect of substituents on the anilinium ions and on the anilines were examined separately using a series of group transfer reaction. <p>

Title:Substituent Effects on the Acidity of Weak Acids. 4. Anilinium Ions
Creators:
Wiberg, Kenneth B.
Uncontrolled Keywords:Protonation, <i>Ab initio</i> calculations, Isodesmic reactions, Ammonium salts, Gas phase acidity, Substituent effects
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:69
Number:12
Page Range:pp. 2183-2192
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20042183UNSPECIFIED
ID Code:2329
Item Type:Article
Deposited On:06 Feb 2009 17:17
Last Modified:06 Feb 2009 16:17

Citation

Wiberg, Kenneth B. (2004) Substituent Effects on the Acidity of Weak Acids. 4. Anilinium Ions. Collection of Czechoslovak Chemical Communications, 69 (12). pp. 2183-2192. ISSN 0010-0765

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