Photooxidation of a platinum-anthracene pincer complex: formation and structures of pt"-anthrone and -ketal complexes

Abstract

Irradiating the cyclometalated pincer complex PtII(DPA)Cl (1, DPA = 1, 8-bis(dlphenylphosphlno)anthracene) In the presence of O2 led to three sequential oxidations of the anthracenyl ring. The first photoproduct, a PtII-9, 10-endoperoxide complex, was converted photochemically to a PtII-9-hydroxyanthrone complex A which was further oxygenated to a PtII-hemlketal (B). The oxidation of A, which could be accelerated by light irradiation, probably Involved a Pt II-anthraqulnone Intermediate. B underwent acid-catalyzed ketalizatlon to form a binuclear Pt2 II-diketal (B1). The photolysis was followed by UV-vls absorption and NMR spectroscopy, and the structures of A and B1 were characterized by single crystal X-ray diffraction. © 2009 American Chemical Society.