As a child, Jean-Pierre Sauvage, PhD, moved often, due to his father’s career in the French army. Postings included North Africa and the U.S. Midwest. But despite the disruptions to his personal relationships and schooling, his interests in mathematics and science remained constant.
That interest in science narrowed to a fascination with chemistry, and culminated in 2016 with Sauvage winning one of the three Nobel Prizes for chemistry for his work connecting molecules with mechanical bonds. The other two winning chemists, who pursued research in the same field, were Sir J. Fraser Stoddart of the U.S. and Bernard L. Feringa of the Netherlands.
A good surprise
Sauvage’s revelation came in 1983 when he was able to create a chain called a catenane, by connecting two ring-shaped molecules together. Molecules usually join in covalent bonds in which the atoms share electrons, but in the chain created by Sauvage they were attached by a “free mechanical bond,” according to the Nobel Prize committee.
“It was a surprise, I did not expect it at all; of course it was a good surprise,” Sauvage said, in remembering when he heard the news of his award. “I was in my office on October 5, preparing myself to look at the Nobel website to see who the winners were. Then half an hour before the official announcement, I picked up the phone. I was not sure at first it was serious.”
The next few months were a whirlwind, culminating with the festivities in Stockholm in December, where he was joined by his family. “It was fantastic; like being on a small cloud,” noted Sauvage. “My impression is that it was like I was in a virtual world. The same was true for the others—we were disconnected from the real world, meeting princesses, kings and queens.”
Sauvage also had the chance to visit four high schools in Sweden and lecture to students. “Each time I delivered a lecture, I was thinking I can make our chemistry very accessible, I can talk about interlocking rings,” he added.
Classrooms, of course, are very familiar to Sauvage. Now formally retired, he still works as a professor emeritus at the “Institut de Sciences et Ingenierie Supramoleculaires” at the University of Strasbourg. He served as director of research at CNRS from 1979 to 2009, when he became a professor emeritus and a visiting professor at Northwestern University.
A very interesting challenge
Sauvage came to his critical scientific discovery by using his expertise in the field of inorganic photochemistry, inspired by the structure of one of the complexes his team was working on at the time. His area of expertise is photochemistry, which involves developing molecular complexes to capture energy from sun rays and using it to power chemical reactions, according to the Nobel Prize committee. The field of topological chemistry, in which researchers interlock molecules, had stalled because chemists had been unsuccessful in creating molecules held together by mechanical chains. When Sauvage and his research team built a model of a photochemically active complex, he realized it was similar to a molecular chain and continued experimenting.
“Those kinds of molecules were considered impossible to make at a reasonable scale in the 1980s,” Sauvage said. “I found that to be a very interesting challenge and I had a good idea of how to make it.”
The approach represents one of Sauvage’s key philosophies of life. “When I was a young faculty member, I was very adventurous, starting my group; I started several groups and projects. If you have an idea that something is very novel, just do it. Use what you know, start in a new field, even if you are not an expert in that field. Be adventurous, be self-confident, if you fail, no one is going to kill you.”
According to information from the Nobel Prize committee, Sauvage’s research group built a ring-shaped and crescent-shaped molecule that were attracted to a copper ion, which held the molecules together. Then the group was able to weld the crescent-shaped molecule to a third molecule representing the first link in a chain. The copper ion was then removed.
The molecular chains, called catenanes, were not only a new class of molecule, but that he had also taken the first step towards creating a molecular machine. In 1994, Sauvage’s research group produced a catenane in which one ring rotated in a controlled manner, one revolution around the other ring, when energy was added.
He and co-winner Stoddart also interacted over the years. “We were such good friends that we did not want to be competitors; we were careful not to overlap with what the other was doing. We had some pleasant and fruitful collaborations.” During his career, Sauvage also spent three years at Northwestern University, where Stoddart teaches, as a part-time visiting professor.
For the most part, though, since attending the University of Strasbourg, Sauvage has remained in the city, happy for a chance to put down roots. When he arrived at the university at age 18, he had moved 15 times in his life. “I told my family I wasn’t moving again, I was staying there, and I did.”
Perhaps his travels growing up made him more adaptable, Sauvage added, and helped form his other key approach to life: Encounters are important. “When you are meeting new people, meeting people with whom you interact, you bring each other ideas,” Sauvage said. “The successes of my groups were related to encounters with various people.”
Jean-Pierre Sauvage, PhD
Award: Nobel Prize in Chemistry, for the design and synthesis of molecular machines
Born: Paris, France
Education: University of Strasbourg
Personal: Married, one married son and one grandson