ANALYSIS OF THE ORTHO EFFECT: BASICITY OF 2-SUBSTITUTED BENZONITRILES

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22340%2F06%3A00016732" target="_blank" >RIV/60461373:22340/06:00016732 - isvavai.cz</a>

Alternative codes found

RIV/61388963:_____/06:00041080

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

ANALYSIS OF THE ORTHO EFFECT: BASICITY OF 2-SUBSTITUTED BENZONITRILES

Original language description

Energies of 18 ortho-substituted benzonitriles and their protonated forms were calculated within the framework of the density functional theory at the level B3LYP/6-311+G(d,p). The substituent effects were evaluated in terms of isodesmic reactions as theeffects on the basicity on the one hand and separately in the nitrile molecules and in the cations on the other. The ortho effect was defined as the difference when compared to the 4-substituted isomers. It is smaller than in the case of ortho-substituted benzoic acids but not negligible (up to 25 kJ mol-1). In unprotonated molecules it may be classified as purely steric effect, in spite of the small dimension of the CN group and estimates made with the calotte models. In the protonated forms, polar properties of the substituent are decisive. In addition, a new, quite important substituent effect was discovered with the substituents OH, SH, CHO and COOCH3, which is controlled by different conformation of protonated and unprotonated mol

Czech name

ANALYSIS OF THE ORTHO EFFECT: BASICITY OF 2-SUBSTITUTED BENZONITRILES

Czech description

Energies of 18 ortho-substituted benzonitriles and their protonated forms were calculated within the framework of the density functional theory at the level B3LYP/6-311+G(d,p). The substituent effects were evaluated in terms of isodesmic reactions as theeffects on the basicity on the one hand and separately in the nitrile molecules and in the cations on the other. The ortho effect was defined as the difference when compared to the 4-substituted isomers. It is smaller than in the case of ortho-substituted benzoic acids but not negligible (up to 25 kJ mol-1). In unprotonated molecules it may be classified as purely steric effect, in spite of the small dimension of the CN group and estimates made with the calotte models. In the protonated forms, polar properties of the substituent are decisive. In addition, a new, quite important substituent effect was discovered with the substituents OH, SH, CHO and COOCH3, which is controlled by different conformation of protonated and unprotonated mol

Type

J_x - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)

CEP classification

CC - Organic chemistry

OECD FORD branch

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Project

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Continuities

Z - Vyzkumny zamer (s odkazem do CEZ)

Publication year

2006

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Collection of Czechoslovak Chemical Communications

ISSN

0010-0765

e-ISSN

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Volume of the periodical

71

Issue of the periodical within the volume

8

Country of publishing house

CZ - CZECH REPUBLIC

Number of pages

17

Pages from-to

1239-1255

UT code for WoS article

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EID of the result in the Scopus database

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