Hermann Staudinger(German:[ˈhɛʁmanˈʃtaʊ̯dɪŋɐ]ⓘ; 23 March 1881 – 8 September 1965) was a Germanorganic chemistwho demonstrated the existence ofmacromolecules, which he characterized aspolymers. For this work he received the 1953Nobel Prizein Chemistry. He is also known for his discovery ofketenesand of theStaudinger reaction. Staudinger, together withLeopold Ružička, also elucidated the molecular structures ofpyrethrin Iand II in the 1920s, enabling the development ofpyrethroidinsecticidesin the 1960s and 1970s.