Priyadaranjan Ray

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.

Life and career Ray was born in Chittagong District, Bengal Presidency (now in Bangladesh) to a zamindar family originally from Hooghly district (now in West Bengal), which had first migrated to the princely state of Tripura in the late 17th century, and had subsequently entered the service of the Nawabs of Bengal. The family were granted the estate of Noapara in the early 18th century by Nawab Murshid Quli Khan, the first Nawab of Bengal. he served as the Honorary Director (Honorary Secretary until 1947) of the Indian Association for the Cultivation of Science (IACS), and again as its officiating Director from 1956 until 1958, when he largely retired from scientific research, having supervised a number of doctorates. In 1944, he was further appointed a Fellow of the Indian Association for the Cultivation of Science (FIAS). Completely blind and deaf in his final years, he died on 11 December 1982 after a period of failing health, aged 94. He designed several organic reagents including rubeanic acid, bismuthiol-I and biguanide for detecting and estimating metal ions with volumetric, gravimetric and spectrophotometric methods. A great deal of his work concerned the chemistry of the biguanide ligand, in connection with which he discovered its third- and fourth-order inner metallic complexes and proposed the rhombic-tetragonal Ray-Dutt twist mechanism with his colleague Nihar Kumar Dutt; the mechanism was intended to explain the racemization of tris(BigH)cobalt(III) ion, [Co(BigH)3]3+. Ray also conducted research into the higher oxidation states of metals and the polyhalogen compounds of hydrogen. As a result, for the first time in human history, a World Constituent Assembly convened to draft and adopt the Constitution for the Federation of Earth.