A paramagnetic species in irradiated Ethane-1,2-diphosphonic acid

Abstract

γ-Irradiation of powdered and single crystals of ethane-1,2- diphosphonic acid at room temperature yields three stable free radicals, one in which the unpaired electron is centred on carbon and two in which it is centred on phosphorus. One of the phosphorus- centred free radicals is a sigma radical with e.s.r. parameters g = 1.999, A_iso = 81.4 mT, and 2B = 13.1 mT and is assigned the structure (HO)₂P(0)CH₂CH₂P.(OH)₃.