Louis Plack Hammett
Encyclopedia
Louis Plack Hammett was an American
physical chemist. He is known for the Hammett equation
, which relates reaction rate
s to equilibrium constants for certain classes of organic reactions involving substituted aromatic compounds. He is also known for his research into superacids and his development of a scheme for comparing their acidities based on what is now known as the Hammett acidity function
. The Curtin–Hammett principle bears his name.
The awards he obtained included the Priestley Medal
in 1961.
Hammett grew up in Portland, Maine
, and studied in Harvard and Switzerland. He earned his Ph.D. at Columbia University
. He authored an influential textbook on physical organic chemistry
, and is credited with coining the term.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
physical chemist. He is known for the Hammett equation
Hammett equation
The Hammett equation in organic chemistry describes a linear free-energy relationship relating reaction rates and equilibrium constants for many reactions involving benzoic acid derivatives with meta- and para-substituents to each other with just two parameters: a substituent constant and a...
, which relates reaction rate
Reaction rate
The reaction rate or speed of reaction for a reactant or product in a particular reaction is intuitively defined as how fast or slow a reaction takes place...
s to equilibrium constants for certain classes of organic reactions involving substituted aromatic compounds. He is also known for his research into superacids and his development of a scheme for comparing their acidities based on what is now known as the Hammett acidity function
Hammett acidity function
The Hammett acidity function is a measure of acidity that is used for very concentrated solutions of strong acids, including superacids. It was proposed by the physical organic chemist Louis Plack Hammett and is the best-known acidity function used to extend the measure of acidity beyond the...
. The Curtin–Hammett principle bears his name.
The awards he obtained included the Priestley Medal
Priestley Medal
The Priestley Medal is the highest honor conferred by the American Chemical Society and is awarded for distinguished service in the field of chemistry. Established in 1922, the award is named after Joseph Priestley, the discoverer of oxygen who immigrated to the United States of America in 1794...
in 1961.
Hammett grew up in Portland, Maine
Portland, Maine
Portland is the largest city in Maine and is the county seat of Cumberland County. The 2010 city population was 66,194, growing 3 percent since the census of 2000...
, and studied in Harvard and Switzerland. He earned his Ph.D. at Columbia University
Columbia University
Columbia University in the City of New York is a private, Ivy League university in Manhattan, New York City. Columbia is the oldest institution of higher learning in the state of New York, the fifth oldest in the United States, and one of the country's nine Colonial Colleges founded before the...
. He authored an influential textbook on physical organic chemistry
Physical organic chemistry
Physical organic chemistry is the study of the interrelationships between structure and reactivity in organic molecules. It can be seen as the study of organic chemistry using tools of physical chemistry such as chemical equilibrium, chemical kinetics, thermochemistry, and quantum chemistry...
, and is credited with coining the term.
Further reading
- Hammond, George S. (1997) Physical organic chemistry after 50 years: It has changed, but is it still there? IUPAC V9. 69, No. 9, pp. 1919-1922.
- Westheimer, F. H. (1997) Biographical Memoirs V72, pp.136-149.
- Young, Robin V., Sessine, Suzanne (1999) World of Chemistry Thomson Gale.