Robert F. Curl Jr., who shared the 1996 Nobel Prize in Chemistry as one of the discoverers of remarkably simple but completely unexpected carbon molecules known as buckyballs, died on July 3 at a retirement home in Houston. He was 88.
His death was announced by Rice University, where Dr. Curl was a professor emeritus of chemistry.
Buckyballs, with their round, hollow structure, upended chemists’ notions of what was possible for the shapes of molecules. A flood of scientists started studying them, spurring the nascent field of nanotechnology and dreams of building molecule-size machines.
Before buckyballs, pure carbon was known to exist in just a few configurations: stacked in sheets as graphite; arrayed in hard, clear crystals of diamond; and jumbled randomly in amorphous carbon.
But in 1985, Dr. Curl, along with Richard E. Smalley, a Rice colleague, and Harold W. Kroto, a scientist visiting from the University of Sussex in England, showed a new configuration: 60 carbon atoms bonded into a molecule that resembled an old-time soccer ball. They also found a larger version made of 70 carbons.
The finding was serendipitous, because they had been looking for something else.
“You could argue it wasn’t any of our areas of interest,” James R. Heath, a graduate student of Dr. Smalley’s who performed many of the buckyball experiments, said in an interview.
The chemists named the molecules buckminsterfullerenes after the architect Buckminster Fuller and his geodesic domes. The name was later shortened to fullerenes or buckyballs.
For the experiment, Dr. Kroto was interested in molecules containing long chains of carbon that had been observed in interstellar space. He hypothesized that the long-chain molecules were created in the atmospheres of carbon-rich red giant stars.
“Harry had studied these in both the laboratory and in using radio telescopes,” said Dr. Heath, now president of the Institute for Systems Biology in Seattle, “but they were very, very transient. And so you couldn’t get a picture of how they were made or how abundant they might be.”
At a science conference in 1984, Dr. Kroto ran into Dr. Curl, an old friend. Dr. Curl told him about an apparatus of Dr. Smalley’s that used a laser to create an intensely hot vapor that coalesced into clusters. Dr. Kroto realized that this apparatus could create conditions similar to those in the atmosphere of a red giant.
Dr. Smalley was less enthusiastic; vaporizing carbon would be a distraction, taking away time from the machine that might otherwise be used for the semiconductor research that he and Dr. Curl were pursuing. Dr. Smalley was even less enthusiastic after a research group at Exxon in New Jersey reported results of a similar experiment with a similar apparatus.
But Dr. Smalley finally agreed to try it, and the three professors, along with Dr. Heath and two graduate students, started their work.
They indeed discovered the long carbon chains that Dr. Kroto had wanted to find.
They also found something else — the buckyballs.
Dr. Heath said Dr. Curl provided a healthy dose of skepticism during the 11-day whirlwind of discovery.
“All of us were like excitable kids,” Dr. Heath said. “And Bob was like the adult in the room. And he would come up with reasons that we had to go back and test and make sure that this was right or that was correct. We all viewed Bob not like he was a devil’s advocate — more like he was an insurance policy. If Bob agreed with you, you were probably right.”
It turned out that the Exxon experiments had also created small numbers of buckyballs, but those researchers had overlooked them in their data. At Rice, the scientists realized what they had found.
“If Mother Nature is trying to tell you something, you have to listen,” Dr. Curl recalled in a 2016 Rice University interview celebrating the 20th anniversary of his Nobel.
While Dr. Kroto and Dr. Smalley pursued further buckyball research, Dr. Curl soon moved on to other areas of interest. In the 2016 interview, he recalled going to Dr. Smalley’s office and finding his colleague filling up binders with papers about buckyballs.
“I don’t want to be in any field for a full-time job keeping up with the literature,” Dr. Curl said. “That’s why I abandoned that area.”
Not many practical uses have been found for buckyballs, but other related forms, like nanotubes (rolled-up tubes of carbon) and graphene (single-atom-thick sheets of carbon) have proved promising.
In 2010, NASA’s Spitzer Space Telescope discovered buckyballs in interstellar space.
In recent years, Dr. Curl turned to economics, working on mathematical models to study matters like energy production and automation.
Robert Floyd Curl Jr. was born on Aug. 23, 1933, in Alice, Texas. His father was a Methodist minister who had helped establish the Methodist Hospital in San Antonio. His mother, Lessie, was a homemaker.
“When I was 9 years old, my parents gave me a chemistry set,” Dr. Curl wrote in an autobiographical sketch for the Nobel Foundation. “Within a week, I had decided to become a chemist and never wavered from that choice.”
In 1954 he received a bachelor’s in chemistry at Rice, then known as the Rice Institute. He earned his doctorate in chemistry at the University of California, Berkeley. After a postdoctoral position at Harvard, he returned to Rice in 1958 as an assistant professor.
He became a full professor in 1967. He retired in 2005, although he continued to work for years.
Dr. Curl married Jonel Whipple in 1955. His survivors include his wife; two sons, Michael and David; and three grandchildren.
After Dr. Curl won the Nobel, Malcolm Gillis, then the president of Rice, asked him what he wanted, perhaps worried that bigger-name institutions would be looking to hire him away from the university.
Dr. Curl asked for a bicycle rack near his office.
“He was an incredibly modest guy,” Dr. Heath said, adding that Dr. Curl did get his bicycle rack.