Results 131 to 140 of about 2,396 (173)

ChemInform Abstract: REACTIVITY OF AN AMBIPHILIC CARBENE. A NONLINEAR HAMMETT CORRELATION

Chemischer Informationsdienst, 1982
AbstractAus dem Chlor‐methoxy‐diazirin (I) entsteht thermisch das Carben (II), dessen Addition an die Styrole (III) zu den Cyclopropanen (IV) untersucht wird.
R. A. MOSS, W. GUO, K. KROGH‐JESPERSEN
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Hammett pσ correlation for reactions of lactoperoxidase compound II with phenols

Canadian Journal of Chemistry, 1993
A stopped-flow kinetic study shows that the reaction rates of lactoperoxidase compound II with substituted phenols are greatly dependent upon the substituent on the benzene ring. Of the 15 phenols studied, it has been possible to relate the reaction rate constants with the ionization constants of 11 phenols by a linear Hammett free-energy relationship:
Hongchang Zhang, H. Brian Dunford
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Correlation Analysis of the Enthalpies of Vaporization of Isomers with the Hammett-Taft Equation

Russian Journal of General Chemistry, 2005
The enthalpies of vaporization of a series of isomeric compounds containing heteroatoms (ketones, alcohols, halo derivatives) are satisfactorily correlated with the Hammett-Taft equation.
R. G. Makitra, I. P. Polyuzhin
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Application of the frontier molecular orbital theory to the interpretation of the Hammett correlation's

Journal of Chemical Education, 1978
The purpose of this paper is to show how a physical explanation of the Hammett relationship may be proposed in the framework of a frontier orbital method which has provided a basis for explaining several aspects of chemical reactivity.
Olivier Henri-Rousseau, Fernand Texier
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Correlation between Hammett Substituent Constants and Directly Calculated π-Conjugation Strength

The Journal of Organic Chemistry, 2006
The results of an energy decomposition analysis of ortho-, meta-, and para-substituted benzylic cations and para-substituted benzylic anions H2C-C6H4Rq (R = H, F, CN, Me, OH, NH2, NO2, CHO, CO2H; q = +, -) are presented and discussed. The calculated values for the pi bonding between CH2(q) and C6H4R show for substituents which have pi orbitals a linear
Israel, Fernández, Gernot, Frenking
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Stereochemical Control Factors in the Hantzsch Thiazole Synthesis:  A Hammett Substitution Correlation Analysis

Organic Letters, 2001
[reaction--see text] It is possible to correlate the distribution of stereochemical products produced during a Hantzsch thiazole synthesis according to the Hammett free-energy equation. This analysis confirms the presumed control of the rate of epimerization during thiazole formation due to stabilization of a cationic transition state intermediate ...
Q, Qiao, S S, So, R A, Goodnow
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Hammett Correlation of Nornicotine Analogues in the Aqueous Aldol Reaction:  Implications for Green Organocatalysis

The Journal of Organic Chemistry, 2005
[reaction: see text] A series of meta- and para-substituted 2-arylpyrrolidines were synthesized and examined for their ability to catalyze an aqueous aldol reaction under buffered conditions. Kinetic analysis of arylpyrrolidine-catalyzed reactions displayed a linear Hammett correlation with rho = 1.14 (R(2) = 0.996), indicating that the reaction is ...
Claude J, Rogers, Tobin J, Dickerson, Andrew P, Brogan, Kim D, Janda   +3 more
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A Hammett correlation for the rates of Diels–Alder reactions of 2-substituted butadienes

J. Chem. Soc. D, 1969
A comparison of two sets of data on the relative rates and isomer ratios of Diels–Alder reactions of 2-substituted butadienes with methyl acrylate and with the methyl acrylate–aluminium chloride complex reveals an excellent Hammett correlation with σ+.
Takashi Inukai, Takeshi Kojima
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Hammett Correlations of Amide Proton Chemical Shifts: An Organic or Spectroscopy Experiment

Journal of Chemical Education, 1995
Experiment designed to illustrate the quantitative relationship between an easily measurable property (amide proton NMR chemical shift) and the electronic effect of several different substituents on substituted benzanilides; includes sample data and analysis.
F. L. Setliff, N. G. Soman, A. D. Toland
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Hammett Parameter and Molecular-Modeling Correlations of Substituent Effects on Esterification Kinetics

Journal of Chemical Education, 2010
The effect of substituents on the rate of reactions is taught extensively throughout organic chemistry. The Hammett equation is useful in quantifying this dependence; however, there are relatively few experiments that investigate this relationship.
Jeremy B. Smith, Houston Byrd, Stephen E. O’Donnell, Will Davis   +3 more
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