PHOTO-CHEMICAL PATHWAYS OF THE DIMERIC, MIXED DIMER, AND MONOMERIC SULFOPHTHALOCYANINES OF COBALT(III) AND IRON(II)

The photochemical reactivity of the dimeric, mixed dimer, and monomeric sulfophthalocyanines of cobalt(III) and iron(II) was investigated by steady-state and flash irradiations. The dimeric species photodissociated into sulfophthalocyanine radicals which were coordinated to either Co(III) or Fe(II) metal centers. Reactions of such intermediates were investigated by interception with alcohols and O2. Also, photoredox reactions were detected with monomeric acidocobalt(III) sulfophthalocyanines. These processes produce the oxidation of the acido ligands (Cl-, Br-, N3-, I-) and the reduction of the metal center. The photoredox dissociation was also investigated by using mixed dimers of the cobalt sulfophthalocyanines with Cr(bpy)33+ and Ru(bpy)32+. The photogeneration of sulfophthalocyanine radicals was observed as a general reaction which was produced by excitation of either the Cr(bpy)33+ or Ru(bpy)32+ units in the mixed dimer. The nature of the reactive excited states involved in the various photochemical reactions of the sulfophthalocyanines of Co(II), Co(III), Cu(II), and Fe(II) is discussed. © 1979, American Chemical Society. All rights reserved.