![Sample our Engineering & Technology journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5933/TOC-Subject-Sample-2021-Engineering-Tech.jpg"})
Abstract
An important pathway in the fading of azo dyes is the reaction with photogenerated singlet oxygen. Singlet oxygen is produced in these systems by the interaction of molecular ground state oxygen with the triplet excited state of the dye. It was found that this process is strongly inhibited in some metal-complexed dyes by triplet energy transfer from the excited dye moiety to the metal ion. The transition metal ions Co(III). Co(II), Ni(II) and Cu(II), which have low lying excited states and may act as energy acceptors, suppress singlet oxygen formation almost completely. Metal ions with empty or with fully occupied d-shells are ineffective as triplet quenchers.