Physical organic chemistry, a term coined by Louis Hammett in 1940, refers to a discipline of
organic chemistry that focuses on the relationship between
chemical structures and
reactivity, in particular, applying experimental tools of
physical chemistry to the study of
organic molecules. Specific focal points of study include the
rates of
organic reactions, the relative
chemical stabilities of the starting materials,
reactive intermediates,
transition states, and products of
chemical reactions, and non-covalent aspects of
solvation and
molecular interactions that influence chemical reactivity. Such studies provide theoretical and practical frameworks to understand how changes in structure in solution or solid-state contexts impact
reaction mechanism and
rate for each
organic reaction of interest. Physical organic chemists use theoretical and experimental approaches work to understand these foundational problems in
organic chemistry, including classical and statistical
thermodynamic calculations,
quantum mechanical theory and
computational chemistry, as well as experimental
spectroscopy (e.g.,
NMR),
spectrometry (e.g.,
MS), and
crystallography approaches. The field therefore has applications to a wide variety of more specialized fields, including
electro- and
photochemistry,
polymer and
supramolecular chemistry, and
bioorganic chemistry,
enzymology, and
chemical biology, as well as to commercial enterprises involving
process chemistry,
chemical engineering,
materials science and
nanotechnology, and
drug discovery.