Hydrophobic acceleration of electron-transfer fluorescence quenching processes between excited 1-alkanoylperylenes and ferrocene derivatives

Coaggregation-facilitated Electron-transfer (ET) fluorescence quenching pro cesses between an excited 1-alkanoylperylene (Pe-n, n = 4, 8, 12) as an acc eptor and an 1-alkanoylferrocene (Fc-m, m = 4, 8, 12, 16) or a 1, 1-dialkan oylferrocene (Fc-m-2, m = 4, 8, 12, 16) as a donor have been investigated b y means of fluorescence spectroscopy in dioxane (DX)-H2O binary solvents of different Phi values, where Phi is the volume fraction of the organic comp onent of an aquiorgano mixture. This is a first observation of an ET proces ses facilitated by hydrophobic-lipophilic interaction (HLI) with organometa llic compounds as donors. The extent of HLI-driven coaggregation between th e acceptor and the donor may be assessed from the efficiency of fluorescenc e quenching, i. e., the slope B of Eq. (2). The chain-foldability effect an d the intramolecular "self-satisfaction'' of HLI for Fc-m-2 have been obser ved. The experimental results show that the behavior of Fc-m as a quencher for fluorescence quenching of Pe-n* is rather similar to that of N-alkylsub stituend phenothiazine.