Hermann Staudinger (; 23 March 1881 – 8 September 1965) was a German organic chemist who demonstrated the existence of macromolecules, which he characterized as polymers. For this work he received the 1953 Nobel Prize in Chemistry. He is also known for his discovery of ketenes and of the Staudinger reaction. Staudinger, together with Leopold Ružička, also elucidated the molecular structures of pyrethrin I and II in the 1920s, enabling the development of pyrethroid insecticides in the 1960s and 1970s. Early work Staudinger was born in 1881 in Worms. Staudinger, who initially wanted to become a botanist, studied chemistry at the University of Halle, at the TH Darmstadt and at the LMU Munich. He received his "Verbandsexamen" (comparable to Master's degree) from TH Darmstadt. After receiving his Ph.D. from the University of Halle in 1903, Staudinger qualified as an academic lecturer at the University of Strasbourg in 1907. He was supported in his work by new his wife Dora Staudinger who wrote up his lectures. It was here that he discovered the ketenes, a family of molecules characterized by the general form depicted in Figure 1. Ketenes would prove a synthetically important intermediate for the production of yet-to-be-discovered antibiotics such as penicillin and amoxicillin. In 1907, Staudinger began an assistant professorship at the Technical University of Karlsruhe. Here, he successfully isolated a number of useful organic compounds (including a synthetic coffee flavoring) as more completely reviewed by Rolf Mülhaupt. Here too he guided future Nobel laureates Leopold Ružička (1910) and Tadeusz Reichstein to their doctorates. The Staudinger reaction In 1912, Staudinger took on a new position at the Swiss Federal Institute of Technology in Zurich, Switzerland. One of his earliest discoveries came in 1919, when he and colleague Meyer reported that organic azides react with triphenylphosphine to form an iminophosphorane (Figure 2). This reaction, commonly referred to as the Staudinger reaction, typically produces a high yield of the iminophosphorane. World War I While in autumn 1914 German professors joined the widespread public support of the war, Staudinger refused to sign Manifesto of the Ninety-Three and joined the few exceptions like Max Born, Otto Buek and Albert Einstein in condemning it. In 1917 he authored an essay predicting the defeat of Germany due to industrial superiority of the Entente and called for a peaceful settlement as soon as possible, and after the entrance of the US he repeated the call in