C&EN: BUSINESS - CATALYZED SUCCESS

LINDA RABER

Growing up on a farm in belmond, a small north-central Iowa town, Lynda K. Johnson learned how to drive a tractor, bale hay, and weed soybeans. "I have wonderful memories of building forts and houses in the straw and hay in the barn, playing in the old windmill, taking walks to the river, and riding our bikes to the lake," she says. Today, at 39, she's not building forts--unless perhaps it is with her children. She is leading a team at DuPont that is building molecules by developing catalysts for olefin polymerization.


	PHOTO BY STEVEN D. ITTEL/DUPONT

Johnson has been at the forefront of applying novel late-metal catalysts to polymerizations for more than 10 years. Her accomplishments encompass and effectively combine both pure and industrial chemistry. Now at DuPont Central R&D in Wilmington, Del., Johnson is the team leader and primary technical driver of the Versipol polymerization technology, as it is being pursued commercially. To date, she has coauthored 28 journal articles and is a co-inventor of 29 published patents and applications.

She believes that her small-town background and strong family have helped her. "For as long as I can remember, I always loved to read and learn, and my parents, teachers, and professors were very supportive of my studies," she says. She believes she benefited from the small size of both the Belmond school system and Wartburg College--a small college in eastern Iowa with an enrollment of about 1,200, where she was an undergraduate. "Both provided lots of opportunities to participate in many activities and fostered close interactions between the students and faculty," she says.

Johnson began college as a math major, but fell in love with chemistry when she took an advanced general chemistry class her freshman year. "I switched to a double major in chemistry and math by the end of the year and have been pursuing this interest in chemistry ever since," she says.

This interest in chemistry has taken her far and has flourished under the guidance of several mentors. "My first exposure to research was as an undergraduate working with Bob [Robert J.] Angelici at Iowa State University during the summer. He did a fantastic job of giving me an interesting project in an area where it was possible to get results in a short amount of time," she says. From this experience, she found that she really enjoyed organometallic chemistry and doing research.

Johnson decided to pursue a Ph.D. in chemistry with Robert H. Grubbs at California Institute of Technology, where she was instrumental in the discovery of highly active late-metal catalysts for olefin metathesis (see page 29). As a postdoc in Maurice S. Brookhart's laboratory at the University of North Carolina, Chapel Hill, her initial concept of sterically encumbered, cationic, late-transition-metal olefin polymerization catalysts was based on kinetic and mechanistic observations derived from low-temperature NMR spectroscopic studies. This concept has been expanded into broad new classes of catalysts by research groups worldwide. It was her fundamental observation of olefin isomerization/reinsertion at the metal center that led her to realize that these catalysts made new forms of polyethylene and other polyolefins. The catalysts also copolymerize ethylene with polar comonomers like methyl acrylate under very mild conditions.

"Both Bob Grubbs and Maurice Brookhart are similar to Angelici in being very nice people as well as excellent scientists and teachers," she tells C&EN. "They both allowed me enough time to understand the systems that I was studying in depth." This approach worked out well in both instances: She ended her graduate career as a co-inventor of the Grubbs ruthenium metathesis catalyst, and her postdoctoral research resulted in the development of the Versipol catalysts.

"The interesting chemistry and the opportunity to work as part of a very talented team have been the best parts of my career at DuPont so far," she says. "The Versipol chemistry has been very much a team effort with scientists at both UNC and DuPont. I've enjoyed working with so many excellent scientists whose strengths, interests, and knowledge are similar, yet complementary," she notes. "Research moves very rapidly when you are working as a member of a large team, and you can learn so much from your colleagues."

In addition to the research on the Versipol systems, Johnson has recently received an assignment on another research program. "Opportunities to work on different areas of science and collaborate closely with experts in many fields are some of the best benefits of working for the central research department of a large and diverse company like DuPont, and I'm excited about being given this chance," she says.

She advises those coming up through the ranks to "believe in yourself, always continue to learn and grow, and be persistent in pursuing your goals." She also notes that "in today's work environment, it's important to be flexible and willing to change. Yet at the same time I think that it is important to follow your interests and stay in a research area or position long enough to truly learn the area so that you can make significant contributions."