Nobel Prize in Chemistry: Dr. Zewail, G'74
Dr. Ahmed H. Zewail,
the Linus Pauling Professor at CalTech who took his Ph.D. at Penn in 1974,
has won the 1999 Nobel Prize in Chemistry for his work leading to the birth
of the field of femtochemistry--a breakthrough that has allowed high--speed
cameras to take pictures of molecules in the process of undergoing chemical
reactions. When he accepts the $950,000 award of the Royal Swedish Academy
of Sciences in Stockholm on December 10, he will be the second Penn alumnus
in three years to win the Prize.*
Dr. Zewail is a dual citizen of the U.S. and of Egypt, where he was born
in 1946. After taking his first academic degrees at Alexandria University--a
B.S. in 1967 and M.S. in 1969--he came to the U.S. to study for his doctorate
at Penn, working with Dr. Robin Hochstrasser, then Blanchard Professor and
now the Donner Professor of Physical Sciences.
"He was a very good student," recalls Dr. Hochstrasser. "He
was always seeking research avenues that would take him into new territory.
He did this as a student and continued with the same approach later. It
was clear from the beginning that he had the potential for an outstanding
research career. His femtosecond laser experiments on the synchronous excitation
of small molecules have had a tremendous impact on chemistry and on the
way in which chemists picture a molecule in the process of undergoing a
After completing his Ph.D., Dr. Zewail spent a year at Berkeley as an
IBM Research Fellow, then joined the faculty at CalTech in 1976. He was
tenured two years later, and became a full professor in 1982. He succeeded
in 1990 to the Linus Pauling Chair of Chemistry, and he continues also as
a professor of physics. His articles and books now number some 300.
The work that has won him the Nobel Prize has already been widely recognized
by the world scientific community. Among his many honors are the Robert
A. Welch Prize Award, Wolf Prize, King Faisal Prize, Benjamin Franklin Medal,
Leonardo Da Vinci Award of Excellence, Röntgen Prize, Paul Karrer Gold
Medal, Bonner Chemiepreis, Medal of the Royal Netherlands Academy of Arts
and Sciences, Carl Zeiss Award, Hoechst Award, and the Alexander von Humboldt
Award--along with numerous prizes of the American Physical Society and American
Chemical Society, the National Academy of Sciences, and others. A member
of the National Academy and a host of honor societies, he has also been
a Sloan Fellow, a Guggenheim Fellow, and a Camille and Henry Dreyfus Teacher-Scholar.
|| The U.S. government has awarded him the E.O. Lawrence Award; Egypt's
President Mubarak conferred on him the Order of Merit, first class, in 1995;
and last year Egypt issued two postage stamps in his honor, an accolade
that touched him, as he told the Pennsylvania Gazette, by putting
him "in the company of stamps honoring the pyramids, Tutankhamen and
In 1997 Dr. Zewail came back to Penn for an honorary degree--one of
six he now holds--and his citation said, in part, "The world scientific
community has applauded your remarkable achievements, heaping upon you its
highest honors...Your greatest honor, however, and the true measure of your
profound effect upon the field will be found in the accomplishments of those
who build upon your work."
* For the 1997 Prize to Dr. Stanley Prusiner, C '64,
M'68, see Almanac
October 7, 1997.
Capturing the Femtosecond
What would a football match on TV be without "slow motion"
revealing afterwards the movements of the players and the ball when a goal
is scored? Chemical reactions are a similar case. The chemists' eagerness
to be able to follow chemical reactions in the greatest detail has prompted
increasingly advanced technology. This year's laureate in Chemistry, Ahmed
H. Zewail, has studied atoms and molecules in "slow motion" during
a reaction and seen what actually happens when chemical bonds break and
new ones are created.
Zewail's technique uses what may be described as the world's fastest
camera. This uses laser flashes of such short duration that we are down
to the time scale on which the reactions actually happen--femtoseconds (fs).
One femtosecond is 10-15 seconds, that is, 0.000000000000001 seconds, which
is to a second as a second is to 32 million years. This area of physical
chemistry has been named femtochemistry.
Femtochemistry enables us to understand why certain chemical reactions
take place but not others. We can also explain why the speed and yield of
reactions depend on temperature. Scientists the world over are studying
processes with femtosecond spectroscopy in gases, in fluids and in solids,
on surfaces and in polymers. Applications range from how catalysts function
and how molecular electronic components must be designed, to the most delicate
mechanisms in life processes and how the medicines of the future should
--From the Academy's Press Release