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Past Winner
2002 Gerhard Herzberg Canada Gold Medal for Science and Engineering

Juan Cesar (Tito) Scaiano

Distinguished University Professor

University of Ottawa

Free radicals and antioxidants. Photo-activated pharmaceuticals. Better sunscreens. Today these are all scientific and medical hot topics that in part owe their coming of age to photochemist Dr. Juan Cesar (Tito) Scaiano's meticulous, three-decades-long probing into the interactions of light and molecules.

Photochemistry, Dr. Scaiano tells students in the first-year classes he loves to teach at the University of Ottawa, asks straightforward yet profound questions: What happens when light hits a molecule? How is the molecule changed? How can it then react with other molecules or atoms? And the particularly beguiling question: How do you study these transitory interactions given that they occur in several billionths-of-a-second?

Dr. Scaiano is a global dean of photochemistry largely because of his insight and technical creativity in finding new ways to accurately and quantitatively study these reactions.

It was the Argentinean-born chemist's work in the late 1960s and 1970s with organic reactive intermediates that led him to the light. Reactive intermediates are among the most difficult molecules to study. Short-lived and in low concentrations, they are molecular stop-over points in chemical reactions. Yet these intermediates are essential to understanding, and ultimately controlling, the dynamics of these reactions.

In the early 1980s, while a research scientist at the National Research Council of Canada (NRC) in Ottawa, Dr. Scaiano pioneered a new way to study and measure reactive intermediates using nanosecond (billionth-of-a-second) laser pulses. The high-speed light could be used to both create the molecular intermediates (flash photolysis) and study them (laser spectroscopy). His automated technique has inspired the design of similar systems in labs around the world.

Through the use of lasers to jump-start chemical reactions and to study them, Dr. Scaiano has developed an encyclopaedic inventory of the reaction rates, transition states and mechanisms of reaction for dozens of important intermediary organic molecules. His more than 500 journal articles have made him Canada's most widely cited chemist.

The technique enabled him to make detailed studies of the behaviour of a medically important group of intermediates, free radicals. His lab's research has provided critical information about how these reactive molecules might affect biological systems.

Dr. Scaiano is pursuing a variety of creative applications of his research findings including ways to prevent the light-induced breakdown of pharmaceuticals, and the development of sensors for DNA damage. He has also created a patented process to prevent the light-induced yellowing of paper, an ongoing problem for Canada's multi-billion-dollar pulp and paper industry.


In June 2000, Dr. Scaiano became the University of Ottawa's first Distinguished University Professor. The title was recognition of his national and international profile. He is the recipient of numerous awards, including an Ontario Premier's Research Excellence Award (1998), the Royal Society of Chemistry's (UK) Sir Christopher Ingold Lectureship and Medal (1998), the Killam Prize for Natural Sciences (1998), and the Porter Medal (1995), presented jointly by the European Photochemical Association, the Inter-American Photochemical Society and the Japanese Photochemical Society.

Dr. Scaiano's lab at the University of Ottawa is a mecca for those interested in the study of organic reaction intermediates. Over the past decade, he has welcomed more than 80 fellow researchers, from undergraduate students to world-leading colleagues, to collaborate on research in his lab.

In 1996, this penchant for encouraging scientific sharing took formal shape as the Reactive Intermediates Student Exchange (RISE) program. Created with four Canadian colleagues, this scholarship program sponsors exchanges of undergraduate chemistry students among 16 Canadian institutions. About 100 students apply annually, and about 20 are selected as scholarship recipients.

He is the founder of Luzchem Research, a small Ottawa-based company that designs, develops, manufactures and markets a specialized line of laboratory instruments for studying the interaction of light with a wide range of materials.

A prodigious author of nearly 500 refereed scientific journal articles, Dr. Scaiano is Canada's only chemist on the list of the 100 most-cited chemists worldwide.

In 1998, Dr. Scaiano became the first non-American editor-in-chief of the scientific journal Photochemistry and Photobiology, an appointment he holds until 2003. He is also on the editorial boards of the International Journal of Chemical Kinetics and Research on Chemical Intermediates.

He has been married for 35 years to Elda, and the couple have four adult children. Characteristic of Dr. Scaiano's peripatetic early career, the children were all born in different countries (Gus in Chile, Veronica in England, Adriana in Argentina and Martin in the United States). Dr. Scaiano notes that, "They are all proud Canadians now."

Professor Scaiano received his Licenciado en Quimica (the equivalent of a B.Sc.) from the University of Buenos Aires in 1967, and completed his Ph.D. in Chemistry at the University of Chile in 1970. After two years of postdoctoral work at University College, London, he returned to Chile in 1972, leaving just prior to the military coup that ousted Chilean president Salvador Allende. Included in numerous research and teaching positions over the next decade were a visiting position at NRC in Ottawa and work in the Radiation Laboratory at the University of Notre Dame in Indiana. In 1979, he began a 12-year research career with NRC, ending as Head of the Reaction Intermediates Group. After being an adjunct professor with the University of Ottawa from 1985 to 1991, Dr. Scaiano joined the university as a professor of chemistry in July 1991.