George C. Pimentel

George C. Pimentel
Name	George C. Pimentel
Birth date	02 May 1922
Birth place	Rolinda, California
Death date	18 June 1989
Death place	Berkeley, California
Fields	Physical chemistry, Chemical physics
Workplaces	University of California, Berkeley
Alma mater	University of California, Los Angeles (B.S., Ph.D.)
Doctoral advisor	William G. Young
Known for	Chemical laser, Matrix isolation, National Academy of Sciences, National Science Board
Awards	National Medal of Science (1985), Priestley Medal (1989)

George C. Pimentel was a pioneering American chemist whose innovative research and dedicated public service left a profound mark on physical chemistry and national science policy. He is best known for his co-invention of the chemical laser and his development of the matrix isolation technique, which revolutionized the study of reactive intermediates. His career at the University of California, Berkeley was distinguished by both scientific breakthroughs and significant leadership roles, including serving as the Deputy Director of the National Science Foundation.

Early life and education

Born in Rolinda, California, Pimentel developed an early interest in science. He pursued his undergraduate studies at the University of California, Los Angeles, where he earned a Bachelor of Science degree. Remaining at UCLA for his doctoral work, he studied under the guidance of William G. Young, completing his Ph.D. in chemistry in 1949. His graduate research focused on photochemistry and kinetics, laying a strong foundation for his future experimental innovations. Following his doctorate, he conducted postdoctoral research at the Massachusetts Institute of Technology before joining the faculty at Berkeley.

Academic career and research

Pimentel joined the University of California, Berkeley faculty in 1949, where he would spend his entire academic career, eventually becoming a professor of chemistry. His most celebrated scientific contribution was the invention of the matrix isolation method in the 1950s, a technique that traps unstable chemical species in an inert solid, such as argon, at extremely low temperatures. This allowed for the first detailed spectroscopic study of free radicals, molecular ions, and other reactive intermediates. His laboratory became a world center for this research, profoundly advancing the field of chemical physics and spectroscopy.

Chemical laser and military work

In the 1960s, Pimentel turned his attention to the nascent field of laser technology. In 1965, with his graduate student Jerome V. V. Kasper, he demonstrated the first chemical laser, a device that generated a population inversion and coherent light directly from a chemical reaction, specifically the photodissociation of chlorine and subsequent reaction with hydrogen. This groundbreaking work, conducted under contract with the United States Army, opened a new branch of laser physics and had significant implications for Department of Defense research into directed-energy weapons and infrared countermeasures.

Public service and policy contributions

Pimentel was deeply committed to the role of science in society and public policy. From 1977 to 1980, he took leave from Berkeley to serve as the Deputy Director of the National Science Foundation in Washington, D.C.. In this role, he helped shape national funding priorities for basic research. He also served on the National Science Board and contributed to influential reports for the National Academy of Sciences. Furthermore, he was the principal editor of the groundbreaking textbook *"Chemistry: An Experimental Science"* and a key figure in the development of the Chemical Education Material Study (CHEM Study) curriculum, which reformed high school chemistry teaching nationwide.

Awards and honors

Pimentel received numerous prestigious awards in recognition of his scientific and educational contributions. He was elected to the National Academy of Sciences in 1966. His highest honors included the 1985 National Medal of Science, awarded by President Ronald Reagan, and the 1989 Priestley Medal, the highest award of the American Chemical Society. He also received the Peter Debye Award, the Wolf Prize in Chemistry, and the IR-100 Award for the chemical laser. He held honorary doctorates from several institutions, including the University of Chicago.

Legacy and death

George C. Pimentel died of cancer on June 18, 1989, in Berkeley, California. His legacy endures through the continued use of the matrix isolation technique in laboratories worldwide, the ongoing development of chemical laser technology, and the lasting impact of his educational reforms. The University of California, Berkeley honors his memory through the Pimentel Hall, home to the College of Chemistry, and the annual Pimentel Lecture. His career exemplified a powerful synergy between fundamental scientific discovery, technological innovation, and dedicated service to the public good.

Category:American chemists Category:University of California, Berkeley faculty Category:National Medal of Science laureates