Gerhard Herzberg

Physical Chemistry

Won the 1971 Nobel Prize in chemistry for using spectroscopy to discover the internal geometry and energy states in simple molecules, and in particular the structure and characteristics of free radicals.

"You shouldn’t do science just to improve wealth — do science for the sake of human culture and knowledge. There must be some purpose in life that is higher than just surviving."

Gerhard Herzberg bends over the piles of paper on his big desk. He is overwhelmed. As director of the Pure Physics Department at Canada’s National Research Council, the fall of 1959 is a very busy time for him. Jack Shoesmith, his research technician, comes into the sun-filled office and walks up to the tall windows overlooking the Ottawa River. He says, casually, “I have an interesting spectrum to show you.”

Herzberg thinks of all the meetings and conferences he has to organize, the paper he is writing, presentations he is preparing and the book he is trying to finish, the third volume of his series Molecular Spectra and Molecular Structure. “I don’t have time for this,” he thinks.

“It’s good,” says Jack.

Reluctantly, Herzberg gets up from his chair and follows the young technician down a flight of stairs to the lab below. It’s a big high-ceilinged room, dimly lit and smelling of ammonia and hot electric wiring. There’s a hint of ozone in the air, as before a thunderstorm. They walk past the special spectrograph that Shoesmith has built — a long steel tube about 50 centimetres high and 3 metres long. Vacuum hoses and electrical wires snake around the base of the apparatus, but the pumps and electricity have been turned off. The big room is quiet except for the murmurs of a small crowd that has gathered in the corner.

Herzberg hurries over to see what they are looking at. A long, thin strip of glass with a seemingly random pattern of vertical lines blackening its surface — a spectrogram — lies on a viewing screen. Recognizing it at once, Herzberg picks it up for a closer look. Instantly he shouts, “That’s it!” and breaks out laughing. “Eighteen years,” he thinks. “I’ve been looking for you for eighteen years.”

What Herzberg held that day was the first spectrogram of a simple chemical called methylene, a molecule consisting of a carbon atom with two hydrogen atoms, one on either side, written CH2. What was special about this? Methylene is a very unstable molecule, a free radical — a transition molecule created briefly in a chemical reaction when molecules come together and transform themselves into something new. Free radicals last only for the length of time it takes for their constituent atoms to rearrange themselves with other molecules into new molecules — a few millionths of a second — so it’s very difficult to obtain a spectrum of such fleeting entities. Herzberg was delighted because the spectrum of the CH2 free radical was a key to proving many outstanding theories concerning the internal structure and energy states of molecules. That particular spectrum that Herzberg identified in 1959 eventually resulted in his winning a Nobel Prize in 1971.

As a young scientist ...

As a 12-year-old in Hamburg, Germany, Herzberg and a friend named Alfred Schulz constructed a homemade telescope. They patiently ground the glass lenses and set them in handmade mounts in a metal tube. On clear nights they used to take the streetcar to the city park and set up the telescope to look at the moon and planets.

In 1933, Herzberg was working as a lecturer at the university in Darmstadt, Germany, when the Nazis introduced a law banning men with Jewish wives from teaching at universities. Since Herzberg had married a Jewish woman in 1929 — Luise Oettinger, a spectroscopist who collaborated with Herzberg on some of his early experiments — he began making plans to leave Germany near the end of 1933. Earlier that year he had worked with a visiting physical chemist named John Spinks, from the University of Saskatchewan. Spinks helped Herzberg get a job at the university in Saskatoon. It was very difficult for German scientists to find work outside Germany; thousands of them were leaving to escape the Nazis and they were all looking for jobs at the same time. When Herzberg and his wife left Germany in 1935, the Nazis let them take only the equivalent of $2.50 each, as well as their personal belongings. Fortunately, before he left, Herzberg was able to buy some excellent German spectroscopic equipment to take with him to Saskatoon. At the time you couldn’t buy such equipment in Canada.

Leaving Germany was very painful for the Herzbergs and they had no idea what they would find in Saskatoon. But Saskatchewan turned out to be a good experience for them, although it was very different from Germany. During the 10 years they lived there, Herzberg taught physics and wrote his famous book Molecular Spectra. His children were born in Saskatoon.

After moving to Chicago for a few years, Herzberg accepted a position with Canada’s National Research Council in Ottawa and was director of physics there from 1949 to 1969. During this time he made his Nobel Prize-winning discoveries in molecular spectroscopy. He worked at the National Research Council as a distinguished research scientist until his death at the age of 94 on March 4, 1999.

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