Priyadaranjan Ray FNA, FIAS (16 January 1888 – 11 December 1982) was an Indian inorganic chemist and historian of chemistry noted for proposing the Ray-Dutt twist mechanism.
Apart from a trip to Europe in 1929–1930, where he worked with Fritz Ephraim and Frederic Emich and underwent surgery to improve his remaining vision, he never left India.
[1] In 1951, in recognition of his accomplishments in microchemistry and colorimetry, he was appointed a member of a IUPAC Commission of New Reactions and served for eight years, during which time he contributed towards a comprehensive review of colorimetric analysis.
[1] A bachelor, Ray lived simply and remained indifferent towards academic honours and distinctions throughout his life, never aspiring to a doctorate despite a record of accomplishments which would have qualified him for one.
[4] He designed several organic reagents including rubeanic acid, bismuthiol-I and biguanide for detecting and estimating metal ions with volumetric, gravimetric and spectrophotometric methods.