Photoinduced oxidation reactions of the pendent macrocyclic complexes: Al(III) phthalocyanine and Ni(II) annulene.

GUILLERMO FERRAUDI; BETTY MATSUHIRO; GUSTAVO T. RUIZ; ALEXANDER G. LAPPIN

POLYHEDRON

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2016 vol. 117 p. 381 - 387

0277-5387

The goal of the work was to expand the understanding of the photoinduced redox reactionsof the Al(III) sulfonated phthalocyanine, HOAlIIItspc, and Ni(II) tertramethyldibenzotetraazaannnulene,[NiII(tmdbTAA)], as components of polymeric structures in which poly(ethyleneimino)and poly(isobutyl-alt-maleate) are the respective backbones of poly(HOAlIIItspc)and poly([NiII(tmdbTAA)]). Saccharide and flavonoid glycosides formadducts that quench the photo-generated oxidizing radicals in the case ofpoly(HOAlIIItspc) with rate constants ¡Ö 1 x 104 s-1,largely independent of reductant structure. The charge-separated intermediate,CS, in the case of poly([NiII(tmdbTAA)]) shows greater reactivitywith the saccharides and flavonoid glycosides, particularly with the flavonoidglycoside rutin where the rate constant is 2.7 x 106 s-1.While phthalocyanine-centered radicals in poly(HOAlIIItspc) werereduced by dAMP (adenosine-5-monophosphate) and CT-DNA, energy transfer withthese reagents competed with the formation of the CS intermediate in poly([NiII(tmdbTAA)]).A study of the intensity of the upper conversion luminescence (¦Ëem< 500 nm), modulated by the concentration of dAMP suggests that this isattributed to the formation of adducts of poly([NiII(tmdbTAA)]) withdAMP that affect the deactivation of the electronically excited Ni(II)tetraazaannnulene pendants before the formation of the CS intermediate