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Inspired Chemistry

Tue, 12/10/2013 - 3:09pm
Paul Livingstone

In helping advance understanding of nanoscale science, the 2013 R&D Magazine Scientist of the Year reveals an uncommon drive to discover.

Dr. James M. Tour. Photo: Rice Univ.In the late 1980s, when setting up his first laboratory, an asst. prof. of chemistry at the Univ. of South Carolina had a conversation with a scientist at IBM Yorktown, Avi Aviram, who had recently authored a paper speculating on a new type of perpendicularly shaped molecule that, if synthesized and equipped with active sensing probes, could be used as a molecular switch for computing.

The young professor politely asked if this molecule had ever been created. “No,” was Aviram’s response, "but it would be great if you could."

To James M. Tour, the chemist in question and the 2013 R&D Magazine Scientist of the Year, the response was an open invitation to try something new. Aviram was delighted to find someone interested in the project, so Tour set out to synthesize it. But when a reporter from Scientific American called to congratulate him on making "the most complex molecule ever synthesized," Tour was in total surprise, knowing that it was far from the most difficult molecule every synthesized. But he readily realized that if he takes his talents and moves into a new field--in this casee from organic synthesis to molecular electronics, an enhanced recognition can be attained. To the Scientific American reporter, he would only concede that it had been “reasonably hard”.

Tour has made a habit of tackling the “reasonably hard”, making numerous discoveries in chemistry and materials, many with the help of students, by not worrying about the level of difficulty. Now the T.T. and W. F. Chao Professor of Chemistry at Rice Univ., Tour has published more than 500 research papers, been awarded more than 100 patents and averages more than 3,000 citations per year. In 2009, he was ranked one of the top 10 chemists in the world by Thomson Reuters.

To protect and serve science
Born in Manhattan and growing up in White Plains, N.Y., Tour did not initially want to be a chemist. He wanted to be a New York state trooper, a dream that was dashed when he was denied academy acceptance because of color blindness. A career in forensics, he decided, would be the next best thing. When he took organic chemistry as part of his studies at Syracuse Univ., however, he loved it.

“I remember I would find an empty classroom on Friday nights and work on all problems at the end of each chapter--problems that had been deemed too hard to be assigned by the professor. That’s how much I loved organic chemistry,” he says. “It really was the first time I found an academic subject that I truly enjoyed doing.”

Tour also distinctly recalls the moment when he began to think carefully about the direction of his career. While in the graduate program in chemistry at Purdue Univ. in the mid-1980s, he was at the thermal printout recorder of his laboratory’s gas chromatograph when his professor, Ei-ichi Negishi, entered the room and began talking about the future of synthetic chemistry. He predicted funding for his area of work would diminish in the coming years as interest in bio-organic and materials chemistry increased. Polymers, in particular, would be an exciting area.

Negishi, who later won the 2010 Nobel Prize in Chemistry and a mentor to Tour, was correct. Important new discoveries were being made in bio-organic chemistry and synthetic organic materials by chemists like Richard Schrock, Robert Grubbs (both recipients of the 2005 Nobel Prize in Chemistry), and George Whitesides.

These breakthroughs fascinated Tour, and he tried his hand in catalysis work. In 1986, Tour began postdoctoral studies at the Univ. of Wisconsin and then Stanford Univ. with Barry Trost, and he recalls binding a new nickel-chromium bimetallic catalyst system to derivatized polystyrene to enhance the catalyst’s stability and selectivity.

It was at Stanford that Tour made several connections that would complete his transition into polymer chemistry. John Stille of Colorado State Univ., a polymer chemist who had transitioned into synthetic organic chemistry, visited the campus and told him to visit IBM Almaden Research Center, where scientists such as C. Grant Willson and Bob Miller were doing advanced work in polymers. Tour spoke with Miller, learning as much polymer chemistry as possible.

IBM would again open a door in an unexpected way when Aviram inspired Tour and his students to synthesize the spirofused molecular switch. What really opened the young chemist’s eyes was the intense level of interest from Scientific American and others. At that point, Tour realized the power of synthetic chemistry: A solution or new product in natural chemistry might take a decade of work, but in just a short time he and his group had gotten widespread recognition. The recognition was undeserved, he believed, but as a young researcher in need of both results and funding, the revelation was important.

One of Tour’s major characteristics is his drive. Colleagues and associates routinely remark on his ability to give 100% to everything he does. A common day for him is to rise at 3:30 a.m., spend two hours studying scripture, spend 90 min at the gym and continue to the laboratory to “begin” the work day. In his early years this included the ability to work endlessly on funding proposals. When he first started his laboratory, he submitted 37 proposals in his first 36 months to agencies like the National Institutes of Health (NIH) and the National Science Foundation (NSF). These proposals took a lot of time to prepare, and his success rate was low. He also began to aggressively file patents—he has been granted more than 100 in his career. This effort became important later in his career when support from industrial licensors of his and his university’s intellectual properties allowed him to achieve some freedom from the vagaries of federal funding. He is now heavily supported by oil and electronics materials companies, who recognize the value of nanotechnology for resource recovery, carbon dioxide capture, transparent conductive displays, and more.

His early funding came from Dept. of Defense laboratories, but eventually he caught the eye of the NSF, and won a Presidential Young Investigator Award for his work in polymers. But his lack of success with funding from NIH compelled him to move fully into organic materials synthesis.

From organometallic reactions, Tour progressed to polymeric creations, such as polyarylenes, polyphenylenes, flame-retardant polymers and conjugated oligomers for electronics and optics. He also synthesized gram quantities and purifications of fullerenes, C60 and C70, using simple column chromatography. This work caught the eye of leading nanotechnologists. Richard Smalley, the discoverer of the carbon fullerene, invited Tour to teach and conduct research at Rice Univ. In 1999, he moved to the Center for Nanoscale Science and Technology, one of the country’s premier locations for nanoscale science.

A transition to nanoscience
At the R.E. Smalley Institute, Tour took an interest in organometallic reaction development, and experimented heavily with carbon nanotubes, molecular electronics and nanomachines. His ability to understand the context of nanotechnology, he says, is an appreciation for the connection between the nanoscale and macroscopic world that he had gained in his polymer chemistry work. He says polymer chemists often consider nanoscale properties, which typically affect properties such as toughness, electrical conductivity and biodegradability in polymeric synthesis. This allows them to transition more easily into the 1- to 100-nm realm of the nanotechnologist.

What was new for him at Rice Univ. was the need to work with non-chemists, such as engineers and physicists, to help transition research into technology. Tour also learned the power of bottom-up construction. Most technology has been achieved by top-down approaches like fashioning an axehead from an ingot that was cut from ore. But biological processes are bottom-up and rely on thermodynamically controlled assembly methods. This molecular toolkit is what has fascinated Tour.

He is also involved in biotechnology, working with medical experts to modify carbon nanotubes to enable delivery. Though the fruits of such research is still decades away, he is hopeful. and to use the inherent nanoparticle antioxidant activity for mitigating tissue degradation.

“We just published a paper on graphene nanoribbon composites where we split nanotubes longitudinally, then alkylated the edges, allowing them to disperse beautifully,” says Tour.

Electronics is also important to the Tour Research Group, and some of the biggest breakthroughs are occurring through graphene and silicon oxides to create devices ranging from transparent memories to supercapacitors for use in batteries and fuel cells.

Research at Tour’s laboratory can seem frenetic, but he does his best to keep his students focused.

“I meet with students twice a week, and every one of them I look in the eye and determine what they are working toward. I want to find out what is driving each one, and I want to make sure they are spending all of their time and intellectual capability on it,” says Tour.

He and his wife invite about 50 students a week into their home for meals. In 2004, at one of these meals, a student was bemoaning that she had been kept up late that night by students in the dormitory room above her playing Dance Dance Revolution. He then went to an arcade to see teenagers playing the game. This now ubiquitous type of game gave Tour an idea, which was driven home by his memory of his wife learning the Book of Psalms through song.

One of the challenges facing school children their inattention in the classroom and their perceived boredom with science. So Tour got the Texas middle school Earth science, life science, and physical science textbooks for 6th, 7th, and 8th-graders. He reduced a each chapter to 10 key bullet points, then recruited a professional Dance Dance Revolution competitor and a composer to develop music and moves to go with the course material.

The program was a hit and eventually developed into an app on Apple’s iTunes store. It has been used by more than 40,000 teachers and downloaded more than 1 million times. Tour had other teaching ideas, and after his success in building both molecular “nanocars” and “nanopeople”, which he called "NanoPutians" after the Lilliputians in the classic Gulliver's Travels, he decided to use these to form a NanoKids program that would help introduce young people to concepts in nanotechnology. This eventually reached 45,000 kids through a 3-D video that was distributed throughout the country.

Part of what sets Tour apart as a researcher is his ability for both self-reflection and the instinct for finding all-encompassing answers. He is as apt to ask a philosophical question as he is to tackle a new idea in materials chemistry, and his answers have been thoughtful and challenging.

“The nice thing about organic chemistry is that you can do it very quickly. In a few hours I can have an answer to a question,” says Tour. He recalls sitting in the library for hours, reading about chemistry. “If I were to do this in any other occupation, people would think ‘What a slouch’. But to get away and think about a project for an hour, and not answer text messages, this allows me to solve something.”

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