UpDate - Vol. 12, No. 32, Page 5
May 20, 1993
Chemistry professor cited as one of most prolific in nation

     Arnold Rheingold began his career as a chemist when he was 13 years
old, but he didn't have a simple, store-bought chemistry set. Instead,
Rheingold got hold of a college-level chemistry book and began
experimenting on his own, making the things that interest young
teenagers-like nitroglycerin and other explosive compounds.
     By the time he was in high school, Rheingold knew he wanted to be a
chemist. Today, the University professor of chemistry and biochemistry is
considered one of the most prolific in the nation, according to a February
article in Philadelphia Magazine.
     The magazine's staff went to the Institute for Scientific Information
(ISI) in West Philadelphia's University City seeking the names of area
scientists to profile. ISI has pioneered citation analysis, a method of
objectively measuring the impact scientists have in their respective
fields, and Rheingold was identified as one of the 12 most influential
scientists in the Philadelphia-Wilmington area, which it described as, "the
sixth-hottest locale for science in America."
     Rheingold published 60 scholarly articles in 1992 and is projecting
over 70 for this year--what he terms a "comfortable" output.
     The scholarly material Rheingold publishes is usually collaborative.
"I work with chemists here at Delaware and other universities at home and
around the world," he said. He currently is working with about 30 different
colleagues. For example, when he was interviewed for the Philadelphia
Magazine piece, Rheingold was trying to identify a crystal structure for a
colleague at England's Cambridge University. The two researchers
communicate internationally via fax and E-mail.
     Sixty-five percent of Rheingold's writing is published in three
journals associated with the American Chemistry Society--The Journal for
the American Chemistry Society, Organometallics and Inorganic Chemistry.
     "I also submit articles to scientific journals in Great Britain,
Italy, Germany and France, just to spread things around," Rheingold added.
     Rheingold's area of most prolific work is in X-ray crystallography,
the definition and design of molecules. "Someone will make a new compound
and want it characterized into a 3-D arrangement of atoms. Not everyone is
trained to do this," he said.
     According to the feature on Rheingold in Philadelphia Magazine, "X-ray
crystallography focuses an X-ray beam on a crystal, and the beam is
diffracted--split into a symmetrical pattern of light and dark spots-by the
regular, ordered pattern of molecules. Each pattern produced by diffraction
is unique and represents the crystal's molecules in coded form. By
interpreting the distribution of spots with computers, scientists like
Rheingold can deduce in minutes the three-dimensional structure of most
crystalline substances, both natural and man-made."
     In the article, Rheingold said many of the compounds he works with are
catalysts with industrial and biological uses. Therefore, a tiny change in
just a few atoms, and how they are bonded into a molecule, could make the
difference between a drug that works properly and one that is ineffective.
     Rheingold also is involved in the synthesis of new compounds that may
have medicinal and industrial uses. He also teaches an upper-level
inorganic chemistry class.
     He got into X-ray crystallography because he was inventing new
compounds that needed molecular identification. Because the waiting time
was too long to have someone else do it, Rheingold decided to complete the
job himself.
     He usually works with a post-doctoral assistant and graduate and
undergraduate students in the crystallography and synthesis labs in Drake
Hall.
     This inorganic chemist starts his day before 8 a.m. in an office
stacked high with papers, journals and correspondence-all mixed in amongst
scholarly texts and manuals. His half-million-dollar laboratory houses two
Siemens Corp. X-ray crystal diffractometers, which are surrounded by walls
Scotch-taped with copies of molecular structures and scientific data.
     Rheingold finishes his day at the office around 6:30 p.m., but he is
far from finished for the evening. He explained that much of the X-ray
crystallography process deals with making mathematical calculations, work
done at home on his personal computer.
     When he was a graduate student, Rheingold recalled that one crystal
structure took two years to complete. Now, the process can take as little
as a day. He is working with Siemens to get the time needed to accomplish
the high-speed data collection process down to only two hours.
     The most satisfying aspect of his job, Rheingold explained, is that he
frequently is the first person in the world to see the molecular structure
of a new compound.
     "I have been through the process hundreds and hundreds of times," he
said, "and I still get goose bumps when I look at the structure of a new
compound, knowing that no one else on the planet has ever seen it."
                                        -Michael Garrett