William L. Jorgensen (born October 5, 1949) is an American chemist specializing in computational and medicinal chemistry, serving as the Sterling Professor of Chemistry at Yale University since 2009, having joined the Yale faculty in 1990.
He is renowned for pioneering computational studies of organic and biomolecular systems in aqueous solution, including the development of the influential OPLS (Optimized Potentials for Liquid Simulations) force fields and TIPnP water models that have enabled widespread modeling of biomolecular processes since the 1980s.
Jorgensen's research integrates free-energy perturbation methods for studying reaction mechanisms, host-guest binding, and equilibria; mixed quantum and molecular mechanics (QM/MM) simulations for organic and enzymatic reactions; and computer-aided drug design targeting proteins involved in infectious, inflammatory, and hyperproliferative diseases.
His approaches have facilitated the discovery of potent inhibitors, such as anti-HIV agents targeting reverse transcriptase and CXCR4, anti-inflammatory compounds against MIF and JAK2 kinase, and anti-cancer drugs for parasitic enzymes like TS-DHFR.
He has also developed key molecular modeling software, including BOSS for simulations, MCPRO for protein folding, and BOMB for generating combinatorial libraries in virtual screening.
Educated with an A.B. from Princeton University in 1970 and a Ph.D. from Harvard University in 1975, Jorgensen previously held positions at Purdue University before joining Yale.
He served as Director of Yale's Division of Physical Sciences & Engineering from 2009 to 2012 and was elected to the National Academy of Sciences in 2011 for his contributions to chemistry and computational biology.
Among his numerous honors are the ACS Award for Computers in Chemical and Pharmaceutical Research (1998), the Joel H. Hildebrand Award in the Theoretical and Experimental Chemistry of Liquids (2012), the Tetrahedron Prize (2015), and the Arthur C. Cope Award (2024).
Early life and education Early life William L. Jorgensen was born on October 5, 1949, in New York City.
His father, Axel V. Jorgensen (1912–1996), had immigrated to the United States from Denmark in 1935 and worked his entire career as an engineer for the Danish firm F. L. Smidth, primarily in midtown Manhattan; he was multilingual, speaking six languages, and earned a B.A. in economics from New York University while attending night classes.
Jorgensen's mother, Alice Lane Jorgensen (1911–1990), grew up in Spokane, Washington, and obtained B.A. and M.A. degrees from the University of Montana and Columbia Teachers College, respectively; many of her relatives had been homesteaders in Montana during the 1920s.
He had one sibling, an older brother named Lane, who later graduated from Lehigh University as an engineer.
The family environment, influenced by his parents' professional pursuits and intellectual discussions, fostered an early curiosity in Jorgensen about scientific and technical subjects.
In 1950, the family relocated from Manhattan to Port Washington on Long Island, where Jorgensen attended St. Peter of Alcantara School through fifth grade.
Following his brother's departure for college in 1960, they moved again to Sherman, Connecticut, and he completed sixth through eighth grade at the local public school, graduating in 1963 as part of a class of 12 students.
During his childhood in these settings, Jorgensen's interest in science was notably sparked in the early 1960s when his parents gifted him a Gilbert Chemistry Set, enabling hands-on experiments with readily available chemicals from local stores, such as potassium nitrate.
He described himself as an adventurous child and directed his path toward chemistry without a singular, predefined ambition.
Education William L. Jorgensen earned an A.B. degree in chemistry from Princeton University in 1970, completing the program in three years thanks to advanced placement credits that allowed him to accelerate his studies.
He initially enrolled in the chemical engineering sequence but switched to chemistry after his first semester, taking key courses in physical chemistry under Professor Walter J. Kauzmann, organic chemistry with Professors Paul von Ragué Schleyer and Ted Taylor, and inorganic chemistry with Neil Bartlett.
During his undergraduate years, Jorgensen joined Professor Leland C. Allen's research group, where he gained early exposure to computational methods through ab initio quantum mechanics and semiempirical molecular orbital calculations using programs like CNDO and NDDO on IBM computers; this work led to his first publication in the Journal of the American Chemical Society in 1970, evaluating these methods for hydrocarbons.
Jorgensen pursued graduate studies at Harvard University, earning a Ph.D. in chemical physics in 1975 under the advisory of Nobel laureate Elias J. Corey.
His doctoral thesis focused on computational aspects of organic chemistry, particularly the development of the LHASA (Logic and Heuristics Applied to Synthetic Analysis) program for computer-assisted retrosynthetic analysis, which built on earlier systems like OCSS and included modules for disconnections, functional group interchanges, symmetry recognition, and synthetic strategies.
This work, conducted initially in assembly language on a DEC PDP-1 and later in FORTRAN on a PDP-10, resulted in two publications in the Journal of the American Chemical Society.
Throughout his graduate studies, Jorgensen maintained interests in quantum mechanics, modifying CNDO codes for MINDO and extended Hückel theory, and collaborating on molecular orbital calculations and 3D plotting techniques, which further honed his computational expertise.
His thesis committee included Corey, William Lipscomb, and R. B. Woodward.
Professional career Positions at Purdue University William L. Jorgensen joined the faculty of Purdue University in August 1975 as an assistant professor in the Department of Chemistry, shortly after completing his postdoctoral work at Harvard University.
This appointment marked his entry into academia, where he received a modest start-up package of $15,000 and a Dreyfus Teacher-Scholar Award, enabling initial investments in computational equipment such as a Texas Instruments minicomputer and a Tektronix graphics display.
At Purdue, Jorgensen established his research program in computational chemistry, focusing on quantum mechanical studies and statistical mechanical simulations of organic and biomolecular systems, while benefiting from the university's access to mainframe computers like the CDC/6500.
Jorgensen was promoted to associate professor in 1979 and to full Professor in 1982, positions he held until his departure in 1990.
During this period, he also served as the Herbert C. Brown Professor of Chemistry and headed the Organic Chemistry Division from 1984 to 1987, roles that positioned him to influence departmental direction and foster interdisciplinary collaborations.
These leadership responsibilities supported the growth of his group, which expanded to include graduate students, postdocs, and collaborators working on projects like the Computer-Aided Mechanistic Evaluation of Organic Reactions (CAMEO) program and early Monte Carlo simulations of liquids.
Notable interactions included serving as an intermediary between Purdue's H. C. Brown and external researchers like Paul Schleyer on carbocation solvation debates, which helped integrate experimental and computational approaches within the department.
Through these positions, Jorgensen built a foundational research program that trained over a dozen coworkers at Purdue, many of whom later advanced to roles in academia and the pharmaceutical industry, laying the groundwork for his subsequent career at Yale.
His tenure at Purdue, spanning 15 years, emphasized the development of computational tools and methods, supported by grants from the National Science Foundation and the National Institutes of Health starting in the late 1970s.
Career at Yale University William L. Jorgensen joined the Yale University faculty in July 1990 as a professor in the Department of Chemistry, bringing with him a research group of 14 members from his prior position at Purdue University, where he had built foundational expertise in computational chemistry.
This transition allowed him to expand his work at Yale, leveraging his established reputation to foster interdisciplinary collaborations within the university's organic and biophysical chemistry communities.
In 2009, Jorgensen was appointed Sterling Professor of Chemistry, Yale's highest faculty honor, recognizing his sustained contributions to the field and leadership in advancing molecular simulations and design methodologies.
Under his direction, he established and led a prominent research group centered on computational and medicinal chemistry, which grew significantly over the decades to incorporate both theoretical modeling and experimental synthesis components.
The group, supported by key personnel such as Senior Research Scientist Julian Tirado-Rives and long-term assistant Paty Morales, emphasized the integration of simulation techniques with practical applications in molecular design.
Jorgensen's leadership extended to extensive student mentoring, guiding approximately 150 researchers, including his first Yale graduate students Erin Duffy and Heather Carlson in 1990 and 1991, respectively.
Many of these mentees pursued successful careers in academia and industry, particularly in pharmaceuticals, reflecting the group's emphasis on training in computational tools, cheminformatics, and synthetic methods.
By the mid-2000s, the lab had expanded to include dedicated synthetic facilities, enabling a seamless workflow from computational predictions to experimental validation.
Post-2020, Jorgensen has continued to direct ongoing drug design projects through his research group, focusing on structure-based approaches to therapeutic targets in areas such as antivirals and infectious diseases, in collaboration with Yale colleagues.
These efforts underscore his support molecular research.
Administrative and editorial roles In addition to his academic positions, Jorgensen held significant administrative leadership at Yale University. From 2009 to 2012, he served as Director of the Division of Physical Sciences and Engineering, overseeing strategic initiatives and resource allocation across departments in chemistry, physics, engineering, and related fields.
Jorgensen played a pivotal role in scientific publishing, particularly as the founding Editor-in-Chief of the Journal of Chemical Theory and Computation (JCTC), an American Chemical Society publication launched in 2005. He led the journal through its formative years, establishing editorial standards and fostering growth in the field of computational chemistry until stepping down in 2022, when Laura Gagliardi succeeded him.
Beyond Yale and JCTC, Jorgensen contributed to governance in professional societies. He chaired the Computers in Chemistry Division of the American Chemical Society in 2002, following as chairman-elect in 2001, and served on the ACS Executive Director's Committee starting in 2004. Internationally, he was president of the International Society for Quantum Biology and Pharmacology from 2001 to 2002. These roles underscored his influence in shaping organizational priorities for computational and theoretical chemistry.
Research contributions Development of computational methods