Chadwick Alma Tolman (October 1938 – April 6, 2024) was an American chemist. He obtained his B.S. in Chemistry from

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a Private university, private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of moder ...

. He earned his Ph.D. in Chemistry as a microwave spectroscopist from U.C. Berkeley under the guidance of William Dulaney Gwinn.

Biography

Tolman joined

DuPont Central Research In 1957, the research organization of the Chemicals Department of E. I. du Pont de Nemours and Company was renamed Central Research Department, beginning the history of the premier scientific organization within DuPont and one of the foremost indu ...

in 1965. His early work was on late transition metal complexes with phosphorus ligands. The Tolman cone angle and

Tolman electronic parameter The Tolman electronic parameter (TEP) is a measure of the electron donating or withdrawing ability of a ligand. It is determined by measuring the frequency of the A1 C-O vibrational mode (ν(CO)) of a (pseudo)-C3v Molecular symmetry, symmetric comp ...

are named after him. In 1972, he proposed the 16 and 18 electron rule, extending

Irving Langmuir Irving Langmuir (; January 31, 1881 – August 16, 1957) was an American chemist, physicist, and metallurgical engineer. He was awarded the Nobel Prize in Chemistry in 1932 for his work in surface chemistry. Langmuir's most famous publicatio ...

's 18-Electron rule to include the many examples of stable 16 electron square planar d⁸ complexes. Later work focused on the activation of C-H bonds by transition metal complexes and free radical oxidation of

cyclohexane Cyclohexane is a cycloalkane with the molecular formula . Cyclohexane is non-polar. Cyclohexane is a colourless, flammable liquid with a distinctive detergent-like odor, reminiscent of cleaning products (in which it is sometimes used). Cyclohexan ...

for the production of

adipic acid Adipic acid or hexanedioic acid is the organic compound with the formula C6H10O4. It a white crystalline powder at standard temperature and pressure. From an industrial perspective, it is the most important dicarboxylic acid at about 2.5 billion ...

, an intermediate in the manufacture of

nylon Nylon is a family of synthetic polymers characterised by amide linkages, typically connecting aliphatic or Polyamide#Classification, semi-aromatic groups. Nylons are generally brownish in color and can possess a soft texture, with some varieti ...

. Tolman was instrumental in the founding of the Delaware Science Alliance and took a year's leave of absence from DuPont to serve as Chair of the Coordinating Committee to help make the Alliance self-sustaining. The primary goal of the Science Alliances was to link scientists interested in education to teachers looking for help in the classroom. Programs include an Elementary Science Olympiad, workshops for volunteers and elementary teachers, summer fellowships in local industry for secondary teachers, and classroom visits and demonstrations by industrial scientists. Upon retirement from DuPont in 1996, Tolman taught at Delaware Technical & Community College and

University of Delaware The University of Delaware (colloquially known as UD, UDel, or Delaware) is a Statutory college#Delaware, privately governed, state-assisted Land-grant university, land-grant research university in Newark, Delaware, United States. UD offers f ...

for a year before joining the National Science Foundation as a program officer in the Chemistry Division. That was followed by two years at the National Academy of Science in the Division of Earth and Life Sciences. His work there included studies and major reports on air pollution and air quality management. Tolman followed and communicated about climate change issues for over 20 years. He wrote a monthly electronic blog, ''Climate Change News''. He helped write the ''Statement of Conscience on the Threat of Global Warming/Climate Change'' for the

Unitarian Universalist Association Unitarian Universalist Association (UUA) is a liberal religious association of Unitarian Universalism, Unitarian Universalist congregations. It was formed in 1961 by the consolidation of the American Unitarian Association and the Universalist Ch ...

which was adopted by their General Assembly in 2006. Tolman served on a number of advisory committees. He chaired the Energy Committee of the Delaware Chapter of the

Sierra Club The Sierra Club is an American environmental organization with chapters in all 50 U.S. states, Washington, D.C., Washington D.C., and Puerto Rico. The club was founded in 1892, in San Francisco, by preservationist John Muir. A product of the Pro ...

, and was a member of the Advocacy Committee of the Delaware Nature Society. He was on the Energy Committee of the Delaware

League of Women Voters The League of Women Voters (LWV) is a nonpartisan American nonprofit political organization. Founded in 1920, its ongoing major activities include Voter registration, registering voters, providing voter information, boosting voter turnout and adv ...

, and the Climate Change Task Force of the U.S.

, where he helped write the Toolkit for Climate Change Action He served on the Greenhouse Gas Reduction Advisory Committee and the Sea Level Rise Advisory Committee of the State of

Delaware Delaware ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic and South Atlantic states, South Atlantic regions of the United States. It borders Maryland to its south and west, Pennsylvania to its north, New Jersey ...

. Tolman was presented the Delaware Audubon Conservation Award at the Delaware

Audubon Society The National Audubon Society (Audubon; ) is an American non-profit environmental organization dedicated to conservation of birds and their habitats. Located in the United States and incorporated in 1905, Audubon is one of the oldest of such orga ...

Annual Meeting on October 9, 2009. Tolman died in Maris Grove, Pennsylvania, on April 6, 2024, at the age of 85.

References

{{DEFAULTSORT:Tolman, Chadwick A. 1938 births 2024 deaths 20th-century American chemists 21st-century American chemists Scientists from Salt Lake City Massachusetts Institute of Technology School of Science alumni DuPont people