Phosphororganische Antioxidantien. I. Kinetik und Mechanismus der Zersetzung von Alkyl-hydroperoxiden durch o-Phenylen-phosphite und -phosphate

Organophosphorus Antioxidants. I. Kinetics and Mechanism of the Decomposition of Alkylhydroperoxides by o-Phenylene Phosphites and Phosphates The reaction mechanism of 2-(2, 6-di-tert-butyl-4-methyl-phenoxyl)-1,3,2-benzodioxaphosphole ( 1 ) with cumyl and t-butyl hydroperoxide has been studied kinetically by means of ³¹P-n.m.r. spectroscopy and high pressure liquid chromatography. 1 reacts with cumyl hydroperoxide to give the corresponding 2-oxide ( 2 ) which with more hydroperoxide and/or water forms the open chained phosphate ester 5 . This acidic phosphate decomposes hydroperoxide catalytically. The kinetic parameters of the separate reaction steps are given. The ionic mechanism of hydroperoxide decomposition is accompanied by a homolytic one in a minor proportion.