Results 131 to 140 of about 3,044 (143)

A theoretical treatment of Hammett's sigma constants

Recueil des Travaux Chimiques des Pays-Bas, 1953
AbstractA theoretical treatment is given of the connection between the structure and the position of a substituent S and the value of σs, from the Hammett equation: log ks/ko = ρ · σs. The theory is based on a wave mechanical calculation of the effect of S on the localisation energy of a reaction. The equations derived make it possible to calculate σs,
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Estimation of Hammett sigma constants of substituted benzenes through accurate density‐functional calculation of core‐electron binding energy shifts

International Journal of Quantum Chemistry, 2005
AbstractFor substituted benzenes such as (p‐F‐C6H4‐Z), Linderberg et al. 1 demonstrated the validity of an equation similar to: ΔCEBE ≈ κσ, where ΔCEBE is the difference in core‐electron binding energies (CEBEs) of the fluorinated carbon in p‐F‐C6H4‐Z and that in FC6H5, the parameter κ is a function of the type of reaction, and σ is the Hammett ...
Yuji Takahata, Delano P. Chong
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RESONANCE INTERACTIONS OF METHYLSULFONYL, METHYLTHIO AND RELATED GROUPINGS AS REVEALED BY HAMMETT SIGMA CONSTANTS

1953
Abstract : The relative acidities of 8 m- and p-substituted thiophenols were obtained to determine the conjugative ability of the MeSO2 was significantly larger than that from BzOH, but smaller than that from phenols or anilines. This indicated the possibility of varying degrees of resonance interactions (involving an expansion of the s valence shell ...
HARRY M. ANDERSEN, F.G. BORDWELL
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Relationship between calculated core‐electron binding energy shifts and Hammett substituent (sigma) constants: I

Journal of Physical Organic Chemistry, 2004
AbstractFor monosubstituted benzenes (Ph‐Z), Linderberg et al. demonstrated the validity of the equation ΔCEBE ≈ κσ, where ΔCEBE is the difference between the core‐electron binding energies (CEBE) of a specific carbon in monosubstituted benzene derivatives (Ph‐Z) and that of unsubstituted benzene (Ph‐H), κ is related to the reaction constant and σ is ...
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A Web Tool for Calculating Substituent Descriptors Compatible with Hammett Sigma Constants**

Chemistry Methods, 2022
Peter Ertl
exaly  

Significance of Hammett and Taft substituent constants on bonding potential of organic corrosion inhibitors: Tailoring of reactivity and performance

Coordination Chemistry Reviews, 2023
Chandrabhan Verma, Akram M Alfantazi
exaly  

ChemInform Abstract: PULSED FOURIER TRANSFORM NMR OF SUBSTITUTED ARYLTRIMETHYLTIN DERIVATIVES PART 3, PROTON DATA AT 100 MHZ AND THE DERIVED HAMMETT SIGMA‐CONSTANT OF THE TRIMETHYLTIN GROUP

Chemischer Informationsdienst, 1975
C. D. JUN. SCHAEFFER, J. J. ZUCKERMAN
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A survey of Hammett substituent constants and resonance and field parameters

Chemical Reviews, 1991
exaly  

The Correlation of Biological Activity of Plant Growth Regulators and Chloromycetin Derivatives with Hammett Constants and Partition Coefficients

Journal of the American Chemical Society, 1963
Toshio Fujita
exaly  

Relationship between calculated core-electron binding energy shifts and Hammett substituent (sigma) constants: I

Journal of Physical Organic Chemistry, 2005
exaly