Formation of photoactive charge-transfer complexes between methyl viologen and sacrifical electron donors. EDTA and triethanolamine

摘要: Mixtures of methylviologen and ethylenediaminetetraacetic (EDTA) acid or triethanolamine (TEOA) in aqueous solutions exhibit a new absorption band which is function the pH with profile consistent requirement that diprotonated amine for TEOA involved complexation. Calculated quantum yields formation complex are value, composition solution, decrease as (donor)/(acceptor) ratio increased. The latter effect suggests excess donor may quench excited state(s) and/or series complexes formed, each its own photoactivity. A mechanism irreversible photogeneration alkaline solution given. 1 figure, table.