Optical and electron spin resonance studies of copper(II), nickel(II) and oxovanadium(IV) complexes of water-soluble phthalocyanine and porphyrazine chelates absorbed on sephadex resins, and the effect of added dithionite

Abstract

Electronic and e.s.r. spectral data show that the solute–solute interactions which prevail in aqueous solutions containing copper(II) and oxovanadium(IV) chelates of tetrasulphophthalocyanines persist when the chelates are absorbed onto the anion exchanger Sephadex DEAE. The distribution of the copper(II) and oxovanadium(IV) into polymeric, dimeric and monomeric species may be adjusted by equilibration of the resin with aqueous solutions containing various amounts of dimethylformamide, which when present in high proportions effects a distribution largely of the monomeric forms. The tetracationic copper(II), cobalt(II) and oxovanadium(IV) tetra-N-methyl-2,3-tetrapyridinoporphyrazine chelates, which are free of solute—solute interactions in aqueous solutions, are absorbed in a monomeric distribution on the cation sites of the cation exchanger Sephadex CM. A two-electron reduction of the copper(II) and oxovanadium(IV) tetrasulphophthalocyanine chelates occurs in their aqueous solution and while absorbed on the resin as a result of reaction with an aqueous solution of dithionite, whereafter the vanadyl complex has a g_∥ value of 2.024. Reduction occurs by electron addition to the macrocyclic ring system.