Hammett, Louis

Hall, Peter Joseph. "The Pauli Exclusion Principle and the Foundations of Chemistry." Synthese 69 (1986) 267272. Hammett, Louis P. Physical Organic Chemistry. New York McGraw-Hill, 1940. 

Haber, Fritz, 129 Haller, Albin, 141, 148 Hammett, Louis, 221, 247, 271 Hannaway, Owen, 60 Hantzsch, Arthur, 54 Harcourt, Vernon, 120, 180, 275 Harkins, William, 239 Harman, Peter, 37... 

Hammett, Louis Plack (1894-1987) American physical chemist, Columbia University New York. 

Louis P. Hammett (1894-1987) was Professor of Chemistry at Columbia University. Hammett, Louis P. J. Amer. Chem. 5oc., 1928,50,2660. Hammett, L. Physical Organic Chemistry. Reaction Rates, Equilibria and Mechanisms, McGraw-Hill, New York, 1970. 

One of the oldest and most familiar quantitative relationships for relating the structure of substituted benzene derivatives to both equilibrium constants and rate constants is the "Hammett Equation." See Louis Hammett, Physical Organic Chemistry, 184199. 

In the 1930s, Louis Hammett and his students measured the strengths of very weak acids and bases, using a weak reference base (B). such as p-nitroaniline (p/C, = 0.99), whose base strength could be measured in aqueous solution. 

Quantitative structure-activity relationship studies are of great importance in modern chemistry. From their origin in the study of organic chemistry dating back to the 19th century, these studies have relied on some empirical and qualitative rules about the reactivity similarities of compounds with similar structures. The most significant development in QSARs occurred with the work of Louis Hammett (1894-1987), who correlated some electronic properties of organic acids and bases with their equilibrium constants and reactivity (Johnson, 1973). Hammett postulated that the effect... 

Oswald, W. (1970) Physikalische Organische Chemie, Louis Plack, Hammett. 

In the 1920s and 1930s, Louis Hammett of Columbia University explored the dissociation of substituted benzoic acids (12.1) in water (Scheme 12.1).2 Changing the R-group on the ring shifts the position of the acid-base equilibrium (Equation 12.8). 

Source Louis P. Hammett, Biographical Memoirs of the U.S. National Academy of Sciences, Vol. 45, 1974, pp. 203-226. 

Louis P. Hammett (1894-1997) invented physical organic chemistry and et Columbia University in 1935 derived the Hammett c/p relationship. The Impact was enormous and in the 1960s chemists were still working out more such correlations. 

Hammett acidity function — The acidity function (H0) was [i] introduced by Louis Planck Hammett (1894— 1987) and co-workers [ii] for characterization of the acidity especially of strong acid solutions of high concentrations. The fundamental idea is the utilization of the protonation of weak bases. The primary systems... 

W. Conard Fcrnelius Louis P. Hammett David N. Jfumo... 

Senior Advisory Board W. Conrad Femelius Louis P. Hammett Harold H. Williams... 

By the organic chemist s approach we can make very good predictions indeed. We can not only account for, say, the relative acidities of a set of acids, but we can correlate these acidities quantiiatively with the relative acidities of another set of acids, or even with the relative rates of a set of reactions. These relationships are summarized in the Hammett equation (named for Louis P. Hammett of Columbia University),... 

Little additional development of QSAR occurred until the work of Louis Hammett (1894-1987), who correlated electronic properties of organic acids and bases with their equilibrium constants and reactivity. Consider the dissociation of benzoic acid ... 

Louis P. Hammett (1894-1987) made two major contributions to physical-organic chemistry the first one (on which wc will focus) is the concept of supcracidity and his acidity function. The. second one is the so-called llammeti equation wiiich concents the correlation of equilibria and rales for reactions of substituted aromatic compounds. With A.H. Deynip. Hammett set up an acidity scale based on the indicator properties of aromatic amines, a. scale that measures 100% sulfuric acid as lo limes as strong as 10% acid, and then showed that this acidity scale was relevant to chemisir> ... 

Louis P. Hammett s classic textbook Physical Organic Chemistry, [5] which opened vistas of a quantitative approach to organic reactivity. It seemed to me that linear free energy relationships might be usefully applied to quantitate car-benic reactivity. For example, although carbenes added to alkenes too rapidly to determine absolute rate constants for these addition reactions, [6] Skell [3] and Doering [4] showed that their reactivity could be described in terms of relative rate constants. 

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