The Scottish-born professor joined the Penn faculty in 1963 and earned wide acclaim for developing laser-based techniques to study interactions between molecules. In the 1990s, Dr. Hochstrasser and other pioneers invented a method for watching molecules change in real time, called two-dimensional infrared spectroscopy.
"It's like taking a molecular movie, watching molecules change their structure," said Eaton, a lab chief at the National Institutes of Health.
Eaton said he and many colleagues thought that Dr. Hochstrasser deserved a Nobel Prize. One of the chemist's former doctoral students, California Institute of Technology professor Ahmed Zewail, did achieve that honor in 1999.
Dr. Hochstrasser may have been overlooked for a Nobel in his lifetime because he delved into so many areas of chemical analysis rather than focusing on one, Eaton said.
"He influenced so many people because he did so many different kinds of novel experiments, then somebody else would take off and make a career out of it," Eaton said.
Dr. Hochstrasser undertook his undergraduate studies at Heriot-Watt University in Edinburgh, then earned a Ph.D. at the University of Edinburgh in 1955. He served in the Royal Air Force for two years, teaching electronics to navigators. He joined the faculty at the University of British Columbia in 1957 and then took a position with Penn.
His final paper was published this month in Nature Chemistry. He and colleagues explained why a drug called rilpivirine is effective against HIV.
Though Dr. Hochstrasser spent the vast majority of his waking hours on chemistry, he was fond of spending time with his grandson, Finnian Kasregis. The two played chess, worked crossword puzzles, and performed card tricks, said Jennie Hochstrasser, the chemist's daughter and the boy's mother.
In addition to his daughter, he is survived by his wife, Carol. Another daughter, Polly, died in 2001.
Donations be made to Penn's Chemistry Discretionary Fund, which supports graduate students, building renovations, and faculty hiring, through University of Pennsylvania Gifts Accounting and Administration, 3451 Walnut St., 433 Franklin Building, Philadelphia 19104.
Contact Tom Avril at 215-854-2430 or firstname.lastname@example.org .