Basicity of carboxylic acids: resonance in the cation and substituent effects

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22310%2F05%3A00013515" target="_blank" >RIV/60461373:22310/05:00013515 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/61388963:_____/05:00021120

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Basicity of carboxylic acids: resonance in the cation and substituent effects

Popis výsledku v původním jazyce

Basic properties of acetic, formic and substituted benzoic acids were investigated by the density functional theory at the levels B3LYP/6-311+G(d,p) and/or B3LYP/6-311++G(2d,2p). The protonated form prefers unsymmetrical conformation E,Z on the two partially double C#O bonds; only in the case of formic acid the E,E form is still observable. Lower basicity of carboxylic acids as compared to ketones is due to the higher energy of the cation while the effect in the uncharged acid molecule is negligible. Contribution of resonance and of the inductive effect was approximately estimated by means of relatively sophisticated model compounds. The inductive effect of the hydroxy group in the cation is the deciding factor for the lowered basicity. Resonance in the cation is strong, stronger than in the acid molecule or in the carboxylate anion, but cannot overcome the inductive effect. Relative basicities of meta- and para-substituted benzoic acids are controlled by the Hammett equation with mark

Název v anglickém jazyce

Basicity of carboxylic acids: resonance in the cation and substituent effects

Popis výsledku anglicky

Basic properties of acetic, formic and substituted benzoic acids were investigated by the density functional theory at the levels B3LYP/6-311+G(d,p) and/or B3LYP/6-311++G(2d,2p). The protonated form prefers unsymmetrical conformation E,Z on the two partially double C#O bonds; only in the case of formic acid the E,E form is still observable. Lower basicity of carboxylic acids as compared to ketones is due to the higher energy of the cation while the effect in the uncharged acid molecule is negligible. Contribution of resonance and of the inductive effect was approximately estimated by means of relatively sophisticated model compounds. The inductive effect of the hydroxy group in the cation is the deciding factor for the lowered basicity. Resonance in the cation is strong, stronger than in the acid molecule or in the carboxylate anion, but cannot overcome the inductive effect. Relative basicities of meta- and para-substituted benzoic acids are controlled by the Hammett equation with mark

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

CC - Organická chemie

OECD FORD obor

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Projekt

<a href="/cs/project/LN00A032" target="_blank" >LN00A032: Struktura a dynamika komplexních molekulových systémů a biomolekul</a><br>

Návaznosti

Z - Vyzkumny zamer (s odkazem do CEZ)

Rok uplatnění

2005

Kód důvěrnosti údajů

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

Název periodika

New Journal of Chemistry

ISSN

1144-0546

e-ISSN

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Svazek periodika

29

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

7

Strana od-do

336-342

Kód UT WoS článku

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EID výsledku v databázi Scopus

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