Photochemically induced hydrogen abstraction by carbon radicals in an adamantane matrix: generation and photochemical cleavage of 2-adamantyl radicals

Abstract

Matrix-isolated cyclic allylic and 1-adamantyl radicals are activated by u.v. radiation to abstract hydrogen or deuterium atoms from the matrix material adamantane and [²H₁₆]adamantane, as is observed by e.s.r. spectroscopy. The 2-adamantyl or 2-[²H₁₅]adamantyl radicals thus formed, undergo a further photochemically induced cleavage reaction, interpreted in terms of a β-CC scission to the (7-bicyclo[3.3.1]non-2-enyl)methyl or (7-[²H₁₅]bicyclo[3.3.1] non-2-enyl)methyl radicals, respectively. From the, latter radicals, the 2-adamantyl (2-²[H₁₅]adamantyl) radicals are regenerated in the dark, presumably by both intramolecular addition and intermolecular hydrogen (deuterium) abstraction from the matrix.