Ab initio determination of substituent constants in a density functional theory formalism: calculation of intrinsic group electronegativity, hardness, and softness

Proft, Frank De; Langenaeker, Wilfried; Geerlings, Pau̧l

doi:10.1021/j100111a018

Cited by 188 publications

(141 citation statements)

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“…These observations led to the utilization in this work of the approximation (6), for the calculation of (f k -) 2 . The two approaches presented above may be summarized in qualitative terms.…”

Section: Resultsmentioning

confidence: 89%

“…The Fukui functions for nucleophilic attack at the anionic carbon atoms of the conjugate bases -CH 2 Z exhibited a clear trend, when compared with the gas-phase acidities of the series. Values calculated by both methods [(f C -) 1 and (f C -) 2 , from equations (4) and (6), respectively] tended to increase with the decreasing acidity of CH 3 Z. This tendency is in agreement with the concept that a greater electronic density [equation (6)] or charge availability [equation (4)] by the anionic carbon atom of -CH 2 Z correspond to less delocalization, and therefore, to a decreased stability of the conjugate base.…”

Section: Resultsmentioning

confidence: 99%

“…Examples include the gas-phase basicity of amines 4,5 , the calculation of electronegativities and hardness values for substituents 6 , the acidity of alcohols 7 , of substituted acetic acids 8 and phenols 9 . An example of the prediction of the unknown acidities of a family of compounds is provided by the calculation of pK a values of hydrofullerenes, based on correlations with various organic acids 10 .…”

Section: Introductionmentioning

confidence: 99%

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A theoretical HSAB study of the acidity of carbon acids CH3Z

Rezende¹

2001

J. Braz. Chem. Soc.

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A acidez em fase gasosa de nove ácidos carbonados do tipo CH 3 Z (nitrometano, acetofenona, dimetilsulfona, acetaldeído, butanona, acetona, acetato de metila, acetonitrila e dimetilsulfóxido ) foi estudada, em busca de correlações com propriedades locais e globais, calculadas em níveis 3-21G, 6-31G* e 6-31+G(3df,2p), segundo a teoria de ácidos e bases duros e macios ("HSAB"). Uma correlação razoável foi obtida com as energias de deprotonação calculadas, o que permitiu estimar a acidez em fase gasosa do tioacetato de metila (∆G o = 1476 kJ mol -1 ), próxima da do nitrometano, o membro mais ácido da série. As funções de Fukui para ataque nucleofílico dos centros aniônicos duros e macios em cada base -CH 2 Z foram usadas para interpretar as variações de acidez quando os ácidos são transferidos da fase gasosa para a fase aquosa.The gas-phase acidity of nine carbon acids of the form CH 3 Z (nitromethane, acetophenone, dimethylsulfone, acetaldehyde, butanone, acetone, methyl acetate, acetonitrile and dimethylsulfoxide) was investigated, in the search of correlations with global and local HSAB properties, calculated at the 3-21G, 6-31G* and 6-31+G(3df,2p) levels. A reasonable correlation was obtained with the calculated ionization energies. Based on the obtained correlation, the gasphase acidity of methyl thioacetate was estimated (∆G o = 1476 kJ mol -1 ) as close to that of the most acidic member of the series, nitromethane. The nucleophilic Fukui functions of the hard and soft anionic centers in each base -CH 2 Z stabilized by direct conjugation were calculated, following two different approaches, and their ratios utilized to interpret the shifts in acidity when the acids are transferred from gas-phase to aqueous solution.

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Section: Resultsmentioning

confidence: 89%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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A theoretical HSAB study of the acidity of carbon acids CH3Z

Rezende¹

2001

J. Braz. Chem. Soc.

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“…The group electronegativity, hardness and softness of 30 organic groups were calculated within the framework of density functional theory, with satisfactory results in comparison with experimental data. 1 A Hammett-like equation was reported for the chemical hardness or the HOMO-LUMO (highest occupied molecular orbital and lowest unoccupied molecular orbital, respectively) gap of a number of molecules, leading to the proposal of hardness substituent constants, similar to the Hammett's s values. 2 The reactivity and stability of particular classes of compounds were explained in terms of local and global density functional theory-based reactivity descriptors.…”

Section: Introductionmentioning

confidence: 99%

Theoretical substituent electrophilicities

Rezende¹,

Millán²

2011

J. Braz. Chem. Soc.

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Uma equação de tipo Hammett, relacionando as eletrofilicidades teóricas globais e de substituinte, foi derivada para etilenos e ácidos benzóicos substituídos, permitindo o cálculo de constantes eletrofílicas para substituintes s w . As constantes teóricas foram correlacionadas com parâmetros cinéticos ou termodinâmicos para vários processos químicos da literatura. Embora formalmente semelhantes às constantes de Hammett, as constantes eletrofílicas para substituintes são obtidas a partir de postulados teóricos inteiramente distintos. As semelhanças e diferenças entre os dois conjuntos de constantes são discutidas e racionalizadas em termos da definição do poder eletrofílico de uma espécie química.A Hammett-like equation, relating theoretical global and substituent electrophilicities, is derived for substituted ethylenes and benzoic acids, allowing the calculation of electrophilic substituent constants s w . Correlations are given between the theoretical s w constants and kinetic or thermodynamic parameters of various chemical processes from the literature. Though electrophilic substituent constants are formally similar to the Hammett constants, they are derived from entirely different theoretical postulates. The similarities and differences between the two sets of constants are discussed and rationalized in terms of the definition of the electrophilic power of a chemical species.

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“…where g min ðH;NH 2 ;F;OH;H;CH 3 ;COOHÞ is the minimum value of the hardness between the different addends A, which corresponds to the hardness of the COOH addend (9.42 eV Table II of [48]). In this table, the value reported is half of that expected due to a different definition of the hardness (Eq.…”

Section: Linear Relationshipmentioning

confidence: 99%

Derivation of the linear relationship between SWCNTs functionalization energies and sidewall curvature

Fusaro

2012

Struct Chem

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A simple linear relationship between the functionalization reaction energies for the exohedral monovalent addition on the surface of an ideal, infinitely long, single-walled carbon nanotube (SWCNT) and the reciprocal SWCNT radius has been derived employing the hardsoft acid basis principle and the tight binding model. The slope of the derived linear relationship is a function of the effective number of valence electrons involved in the functionalization reaction. The intercept of the derived linear relationship, equal to the reaction energies on a planar graphite surface, is a function of the electrophilicity of the monovalent addend and of the condensed Fukui function of its reacting atom. The theoretical predictions of this simple formula are coherent with the computational density functional theory data reported in the literature.

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Ab initio determination of substituent constants in a density functional theory formalism: calculation of intrinsic group electronegativity, hardness, and softness

Cited by 188 publications

References 4 publications

A theoretical HSAB study of the acidity of carbon acids CH3Z

A theoretical HSAB study of the acidity of carbon acids CH3Z

Theoretical substituent electrophilicities

Derivation of the linear relationship between SWCNTs functionalization energies and sidewall curvature

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