Odd Hassel

Odd Hassel was born on May 17, 1897, in Christiania. He studied mathematics, physics, and chemistry at the University of Oslo before working in Munich with Kasimir Fajans and at the Kaiser Wilhelm Institute in Berlin, where he mastered X-ray crystallography.

Returning to Oslo, Hassel became head of physical chemistry and pioneered electron diffraction in gases to determine the three-dimensional geometry of molecules. In 1943, he proved that cyclohexane adopts a strain-free chair conformation with distinct axial and equatorial bonds, revolutionizing organic stereochemistry. During the Nazi occupation of Norway, he was arrested and held in Grini concentration camp. In 1969, he shared the Nobel Prize in Chemistry with Sir Derek Barton.