Issue Date: February 12, 2007
James M. Tour
A pivotal point in James M. Tour's career occurred when his graduate thesis advisor at Purdue University, Ei-ichi Negishi, informed him that, because of declining funding, there was little future in traditional organic synthesis.
That was precisely where Tour seemed to be headed. His interest in chemistry had been whetted by his father, a pharmacist, and by a chemistry set that opened the door to glorious miniexplosions, fires, and other chemical transformations. The young Tour fell in love with synthetic organic chemistry as an undergraduate at Syracuse University. As his studies continued at Purdue, and then as a postdoc at two other universities, he gained a strong background in the art of organic synthesis and organometallic chemistry.
But as Negishi had warned, funding for organic synthesis was drying up, so Tour decided to apply the tools of modern organic synthesis to making polymers, where he could get "a lot of bang for the buck." He voraciously absorbed as much as he could about polymer chemistry, and it paid off: As a faculty member at the University of South Carolina, Columbia, from 1988 to 1999, Tour became an early leader in the chemistry of organic materials. His interests branched out from polymers to molecular electronics to fullerenes and carbon nanotubes and related areas.
His nanotechnology-related research got a big boost when he moved to Rice University in 1999, at the invitation of the late fullerene pioneer Richard E. Smalley. At Rice, the 47-year-old Tour wears several hats, emblematic of his research interests: Chao Professor of Chemistry, professor of computer science, professor of mechanical engineering and materials science, and director of the Carbon Nanotechnology Laboratory at the Smalley Institute for Nanoscale Science & Technology.
Early on, Tour attracted interest from the polymer research community when he synthesized conjugated oligomers of precise length, followed by sheetlike polymers that are fully conjugated and constrained to a planar conformation.
Among his many achievements in molecular electronics, Tour devised a method for building computer systems from disordered arrays of organic and metallic components, and he later demonstrated the utility of this approach in an array called the NanoCell. Although some computer scientists scoffed at the idea that such disordered arrays would be programmable, Tour showed that they are, Smalley once said.
In the fullerene field, when most researchers were struggling to isolate pure C60 in milligram quantities, Tour's group found a simple way to purify gram quantities of buckyballs, using activated charcoal as the stationary phase in column chromatography. He followed this with similar routes for large-scale isolation of higher fullerenes using other stationary phases. These purification methods have been widely used, according to Smalley.
In the hot area of carbon nanotubes, Tour developed a method based on diazonium chemistry for functionalizing nanotubes without the use of any solvent. Prior to his technique, 2 L of solvent were required per gram of nanotubes, making solvent-based functionalization cost-prohibitive for any industrial process. Functionalized nanotubes are needed for making reinforced composites. Tour and his coworkers have shown that incorporating such nanotubes in polymers imparts the resulting composites with remarkable properties. A composite rubber containing nanotubes is currently headed to market, Tour says.
When asked which of his achievements he's proudest of, Tour mentions two projects that have garnered him enthusiastic public attention. One involves single-molecule nanocars and other nanoscale vehicles that might be used to transport molecular cargo on surfaces. The other project involves person-shaped molecules dubbed NanoKids, which provide a means for getting real-life kids interested in chemistry and nanotechnology. Some scientists have carped about the value of these much publicized projects, but Tour is convinced he's touching a lay community that many of his scientific colleagues are having difficulty reaching.
One thing no one can argue about: When it comes to organic chemistry, Tour has the energy, creativity, and enthusiasm to make it come alive, even for nonchemists.
- Chemical & Engineering News
- ISSN 0009-2347
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