In the early 1950s, Woodward, and British chemist Geoffrey Wilkinson, proposed a structure for ferrocene, a compound consisting of a combination of an organic molecule with iron. This marked the beginning of the field of transition metal organometallic chemistry. The field later grew which grew to be important to the chemical industry. Wilkinson won the Nobel Prize for this work in 1973, with Ernst Otto Fischer. Some historians think that Woodward should have shared this prize along with Wilkinson. Woodward himself thought so, and voiced his thoughts in a letter sent to the Nobel Committee.