Riboflavin as a photocatalyst and hydrogen carrier in photochemical reduction.

摘要: 1. 1. In the presence of certain metal-chelating agents riboflavin was reversibly reduced by visible light. This reduction has been followed visually, spectrophotometrically and polarographically. 2. 2. Riboflavin not only absorbs light but is in process, turn can transfer its electrons to suitable hydrogen acceptors added system. 3. 3. Polarographic data were used establish reversibility photoreduction system. Semiquinone formation strongly suggested. 4. 4. From half-wave potential (E12) for polarographic riboflavin, at pH 7.3 calculated be −0.208 volts, −0.194 volts 7.0. 5. 5. Oxygen inhibited also protected from photolysis. Na2EDTA promoted photoreduction. 6. 6. Certain metal ions, dinitrophenol, p-nitrobenzaldehyde, sodium azide riboflavin. inhibition could reversed excess riboflavin. 7. 7. Evidence points a metal-mediated complex between or light-activated agent.