PHOTOCHEMICAL AND SPECTRAL PROPERTIES OF A PARTICULATE MODEL SYSTEM OF CHLOROPHYLL WITH AMPHIPHILES PREPARED FROM HISTAMINE

摘要: — In the photosynthesis model system described, chlorophyll a at an interface photosensitizes transfer of hydrogen equivalents from hydrocarbon phase to aqueous phase. The phase, which is adsorbed, consists polyethylene particles swollen with tetradecane. are also charged positive by co-adsorption dodecylpyridinium iodide. Furthermore, ligated imidazole function one several amphiphiles derived histamine, may or not contain reducible nitroaromatic group that can serve as primary electron acceptor photoexcited chlorophyll. fluorescence quantum yield on these diminished self-association pigment and reaction oxidizing amphiphile; in latter case, correlated one-electron redox potential amphiphile. Fluorescence-lifetime analysis reveals most excited singlet states quenched rather quickly, comes small fraction long lifetime. All preparations sensitize photoreduction 5,5′-dithiobis(2-nitrobenzoate) (DTNB) water-soluble thiolate hydrazobenzene. When amphiphile ligates oxidizing, unrelated particles, but be related degree kinetics DTNB require passes through oxidant DTNB. Quantum yields for photosensitized reducton absence have reversed correlation potential, rationalized terms Marcus theory transfer. data consistently accounted if photoproduct ion pair when available, radical it not, both formed state