Philip Stephens Named to Royal Society
USC College chemist recognized for his groundbreaking work analyzing molecular structure.By Wayne Lewis
June 1, 2008
The Royal Society, founded in 1660, is the United Kingdom’s equivalent of the United States’ National Academy of Sciences.
A College faculty member for more than 40 years, Stephens is renowned for his now-widely used techniques investigating the structures of molecules using light.
USC College Dean Howard Gillman said the honor was richly deserved.
“The Royal Society’s decision to include Philip in its ranks confirms what we at USC — and his colleagues worldwide — have long known,” Gillman said. “He is a world-class chemist whose pathbreaking work in spectroscopy has expanded the frontiers of his field and has had a monumental real-world impact.”
In the Royal Society’s announcement, Stephens was cited for his “introduction and development of two major techniques for characterizing … molecular structure.”
One of four chemists in the Royal Society’s 2008 class of 44 fellows, Stephens has conducted foundational research in the fields of magnetic and vibrational circular dichroism spectroscopy.
Using these breakthrough techniques, scientists can more accurately observe the structure of organic and metal-infused molecules. These developments are at the heart of making pharmaceuticals safer and more effective, among many other applications.
Stephens was thrilled to receive the honor.
“It’s one of the most exciting moments in my career, especially as I’m British,” said the West Bromwich native. “It’s very wonderful.”
Mark Thompson, professor and chair of chemistry in the College, lauded Stephens’ service to his university and to his discipline.
“Philip led the department for six years as the chemistry department chair in the early 1990s, and is now being recognized for his scientific leadership by the Royal Society by being named a fellow,” Thompson said.
“This is a very distinguished and well-deserved honor.”
Since 1964, Stephens has authored more than 200 papers published in peer-reviewed scientific journals. He has delivered and presented almost 200 invited lectures and conference papers.
A 1968 Alfred P. Sloan Research Fellowship funded his early work in the College. In 1975 USC presented him with its Associates Award for Creativity in Research. Nine years later he received a Guggenheim Fellowship for a sabbatical year at the University of Sussex.
The key use of Stephens’ development of vibrational circular dichroism (VCD) spectroscopy determines the structures of chiral molecules, which have two forms — nonsuperimposable mirror images, comparable to left and right hands.
The left- and right-handed forms of a chiral molecule respond differently to circularly polarized light waves. Using Stephens’ VCD technique, chemists can differentiate between and analyze them.
All of the molecules inside the human body are chiral, as are some molecules used as pharmaceuticals. Sometimes the left-handed form of a drug can be more effective, with fewer side effects, than its right-handed counterpart.
In some cases, most infamously the sedative thalidomide, one molecule can provide effective treatment while its mirror image proves catastrophically toxic. The U.S. Food and Drug Administration requires testing of both forms of a chiral drug. Pharmaceutical companies analyze chiral drugs using VCD spectroscopy.
Stephens earned his B.A. and D.Phil from Oxford University, then did postdoctoral work at the University of Copenhagen in Denmark and at the University of Chicago.
As a doctoral student at Oxford, Stephens focused his research on the Faraday effect — the observation by legendary 19th century scientist Michael Faraday that the behavior of light could be altered by strong magnetic fields.
Building on Faraday’s observation, Stephens developed the theory of magnetic circular dichroism (MCD) spectroscopy at Oxford and during his postdoc years. Upon his arrival at USC College in 1967, he began creating an instrument to measure MCD.
By the mid-1970s he had expanded his work to develop VCD spectroscopy. This new endeavor expanded the spectrum of light used to measure VCD into the infrared. Using this technique, chemists examine the three-dimensional structures, or stereochemistries, of molecules based on their vibrations.
Subsequent research by Stephens used quantum mechanical theory to predict VCD. He also developed quantum-based computational techniques now integrated into ubiquitous software used for molecular analysis.
In his MCD and VCD spectroscopy investigations, Stephens has collaborated with distinguished colleagues such as National Academy of Sciences members Harry Gray, Arnold O. Beckman Professor of Chemistry at Caltech; Edward Solomon, Monroe E. Spaght Professor of Chemistry at Stanford University; and Kenneth Wiberg, Eugene Higgins Professor of Chemistry at Yale University.
“Philip’s just a stellar scientist,” Solomon said. “He’s made seminal contributions in two very important areas. Very few people can say they’ve made this kind of impact.”
Gray described Stephens’ work as “truly pioneering,” adding that “[h]is election to membership in the Royal Society is richly deserved — and long overdue!”
The January 2008 issue of Theoretical Chemistry Accounts was a Festschrift dedicated to Stephens.
“Professor Stephens’ contributions to molecular spectroscopy are fundamental and span both theoretical and experimental aspects and applications ranging from organic to bioinorganic chemistry,” his former students Gerard Jensen of Gilead Sciences in San Dimas, Calif., and Karl Jalkanen of the Curtin University of Technology in Australia wrote in the Festschrift.
“No other individual has contributed more to pioneering the fields of [MCD and VCD].”
In recent research, Stephens has explored the structures of natural products — derived from plants and organic molecules — with implications for the treatment of cancer, heart disease and other maladies.
Stephens will be recognized at a special reception on campus to be organized in the fall.
He noted that support for the chemistry department from the university and the College has greatly benefited his research over the years.
“I’m very grateful to USC,” he said, a smile lighting up his face.