Intriguing multichannel photoinduced electron transfer in lanthanide(III)–diphenylamine systems

摘要: Photoinduced electron transfer (PET) and charge (CT) interactions of trivalent lanthanide ions (Ln3+) with a fluorogenic diphenylamine (DPA) donor in aqueous solution have been investigated. Present donor–acceptor systems relevance to the leaching out mitigation geoenvironment where DPA finds its presence as industrial agricultural waste. The formation weak ground state CT complexes present is confirmed from absorption studies. There no emissive exciplex evidenced steady-state (SS) fluorescence measurements. SS quenching results, however, indicate substantial static quenching, attributed complex formation. Time-resolved (TR) results show quite efficient dynamic process. It established that TR by not due energy but PET excited Ln3+. Direct evidence for mechanism obtained laser flash photolysis measurements transient band at around 670 nm cation clearly evident. time constant growth confirms occurs S1 ions. No correlation is, observed estimated constants free changes reactions, participation multiple channels involving vacant electronic states As realized, are acceptors reactions many extensive follow up studies expected understand details multichannel these geologically important redox systems.