The Nobel Prize in Chemistry 1969 was awarded jointly to Derek H. R. Barton and Odd Hassel "for their contributions to the development of the concept of conformation and its application in chemistry".
 

Odd Hassel had limited success analysing the structure and properties of simple molecules, until he used a technique that fires electrons at a sample and creates an interference pattern characteristic of the molecule in question. The focus of his attention was cyclohexane, a compound that in two dimensions is represented by a hexagonal ring of carbon atoms, but their electron interference patterns revealed a more complex geometry. In a modest four-page article published in 1950, Barton proposed the shape of the cholesterol molecule and its chemical relatives, which contain several rings of carbon joined together. More importantly, he proposed that different configurations of these molecules affect fundamental characteristics. Barton's observations almost immediately solved the problems chemists had in grasping inexplicable details about the behaviour of chemicals.