 Ketenes were systematically investigated by Hermann Staudinger in 1905 in the form of diphenylketene (conversion of formula_1-chlorodiphenyl acetyl chloride with zinc).Staudinger was inspired by the first examples of reactive organic intermediates and stable radicals discovered by Moses Gomberg in 1900 (compounds with triphenylmethyl group).Ethenone, the simplest ketene can be generated by pyrolysis (thermal cracking) of acetone