HE earned his PhD in chemistry at age 22. By 34 he had been awarded a prestigious MacArthur Prize Fellowship. In 1984, Science Digest magazine named him one of the nation's brightest scientists under 40. Yet ask him where his interest in chemistry started, and he brings up comic books.
``My brother and I responded to one of those ads in the back of comic books: `Sell seeds and become a millionaire,''' says Mark S. Wrighton, who chairs the Department of Chemistry at the Massachusetts Institute of Technology. ``We didn't become millionaires,'' he chuckles, ``but we got enough points to get a chemistry set.''
As a 10-year-old growing up in Tennessee, he says, he enjoyed playing with the set - even when one of his less-fortunate experiments spilled on the hardwood floor of his bedroom. ``I wiped it up and didn't tell anybody. The next day the floor was black, and I remember having to convey this news to my father. I was very pleased with the way he took it, and I learned a lot - especially about finishing floors.''
His father, who was at the Naval Air Station in Memphis, was not a college graduate. ``But I was encouraged by my parents to do things that were interesting to me, and there was always an implied agreement that I would go to a higher level of education than either of my parents.''
What interested him when he arrived at Florida State University as a freshman, however, was not chemistry but government and mathematics. ``I'd done physics and chemistry in high school,'' he recalls, ``but it wasn't something that really stimulated me. In fact, I thought I was better in writing and communication.''
That first semester in college, however, he enrolled in a chemistry course. ``And within three weeks my chemistry was so exciting that I decided I wanted to become a chemistry major.'' Why? ``The instructor was just fantastic, and brought out things that really showed me that chemistry could be very interesting.''
The following summer, after changing majors, he wrote to his departmental adviser, Jack Saltiel, to ask whether he could work for him washing glassware. He ended up doing an independent project in Professor Saltiel's laboratory - even though he had completed only one year of college at the time.
And that experience, for Professor Wrighton, speaks to the particular appeal of chemistry. Unlike some other sciences, he says, ``you can see a lot of things, and you can actually do the science at a relatively early stage while learning it. That's the excitement - actually doing things that you can see happen. It is incredibly fun.''
Now and then he visits the classes of his 12-year-old and 8-year-old children, he says, ``to demonstrate what I call `kitchen chemistry.' I bring chemicals from our kitchen at home, like vinegar and baking soda, and I show them the pH of a Coke, or I demonstrate how to make batteries and fuel cells.''
Much of today's chemistry, he notes, is done by teams of researchers. But he notes that ``it's still true that a single individual can pose a problem. You can set out to make a substance, and you can prove you've done it, with your own hands, generally within the confines of a single building.'' By contrast, he says, a researcher in high-energy physics could end up co-authoring a paper with as many as 500 other people.
What qualities make a good scientist? ``The distinguishing feature is curiosity about the way things work,'' says Wrighton. In addition, scientists have to ``be willing to do things repetitively - to test things. An element of patience is necessary.''
Wrighton suspects scientists are no brighter than other people. ``Most people have the threshold level of intelligence'' to do science, he says. He notes, however, that ``in science, one has to be willing to work hard.''
Looking ahead, Wrighton sees three issues that ``really drive chemistry at the moment.''
Instrumentation. ``When I started in chemistry, no one even had an electronic calculator - they didn't exist.'' Now nearly every instrument has its own computer attached. The result: better and faster research, with ``higher-resolution answers to the questions we ask,'' and an ability to probe molecules and systems far more complex than those that could be studied several decades ago.
Pharmaceuticals. Chemists are deeply involved in making derivatives from naturally occurring products and in synthesizing new products.
Materials. ``Many organic chemists are not as familiar with the problems in composite structures as with problems in human health,'' he notes. ``But today, materials are just as important.'' Wrighton points to polymers, adhesives, and superconducting materials as among the many areas in which chemistry has helped produce new substances.
Connecting these three areas, he says, is the fact that chemists are increasingly studying complex systems, where an understanding of the phenomena can only arise by looking at the entire system rather than its pieces. In areas as diverse as global climate change and micro-electronics, he says, the chemistry of complex systems continues to have a strong input. The result is increasing cooperation across disciplinary lines. ``For the first time in my years as a chemist,'' he says, ``we're getting interested in shaking hands and really working collaboratively with people outside our building.''
For Wrighton himself, the most interesting areas are those in which molecular materials can be put together ``to achieve functions analogous to either biological systems or solid-state electronic systems.'' One area of his research is the molecular-based transistor. ``The first electronic chips were this big,'' he says, pointing to his thumbnail, ``and they had one transistor. Now they are that big and have a million.'' He foresees the creation of single large molecules that function like transistors.
Also coming in the future, he says, will be significant advances due to instrumentation. One example: Femtosecondspectroscopy, analogous to stroboscopic photography, which will allow stop-action views of molecules on a scale measured in increments of 10 -15 (1/1,000,000,000,000,000) seconds. ``Imagine being able to look at the atoms in a molecule as it flies apart!'' he says.
Also on the horizon are much better ways to explore the minuscule distances - on the order of ten angstroms (one hundred-millionth of a centimeter) - that separate reactants from the surfaces of catalysts. ``It's that same region of space that controls friction and wear, that controls micro-electronics, that controls many membrane processes in biology,'' he says, noting that ``it's a dimensional regime that hasn't been well covered by chemistry.''
How will these advances be relevant to the world at large? Chemistry, says Wrighton, has a long record of positive contributions to technology. ``I view our role in science as laying the basic groundwork for making prudent choices for technology. Our role will be to elaborate all the ways to do things, while illustrating new things about matter and nature.''
`INSIDE THE SCIENCES' Nov. 6 Botanist Peter Raven Nov. 13 Biologist Lee Hood Nov. 20 Physicist Shirley Jackson Nov. 27 Archaeologist Robert Adams Dec. 4 Astronomer Sidney Wolff Dec. 11 Chemist Mark Wrighton Dec. 18 Particle physicist Leon Lederman Dec. 22 (Fri.) Space scientist James Van Allen Dec. 29 (Fri.) Conclusion