Micelle-Enhancing Effect on a Flavin-Photosensitized Reaction of Benzyl Alcohols in Aqueous Solution

• Published in: Bulletin of the Chemical Society of Japan Vol. 76; no. 3; pp. 601 - 605
• Main Authors: Yasuda, Masahide, Nakai, Takuya, Kawahito, Yasumasa, Shiragami, Tsutomu
• Format: Journal Article
• Language: English
• Published: TOKYO The Chemical Society of Japan 01.03.2003; Chemical Soc Japan; Chemical Society of Japan
• Subjects: Chemistry; Chemistry, Multidisciplinary; Physical Sciences; Science & Technology; MONOAMINE-OXIDASE; OXIDATION; OXYGEN; PERCHLORIC-ACID; DIMETHYLTHYMINE CYCLOBUTANE DIMER; REDOX CHEMISTRY; MONOMERIZATION; PHOTOCATALYSTS; EFFICIENT; PARTICIPATION
• ISSN: 0009-2673; 1348-0634
• DOI: 10.1246/bcsj.76.601

The tetra-O-acetylriboflavin (Fl)-photosensitized dehydrogenation of benzyl alcohols 1 proceeded more efficiently in aqueous solutions in the presence of sodium dodecyl sulfate (H2O/SDS) than acetonitrile solutions. The fluorescence quenching of Fl with 1 occurred efficiently in H2O/SDS. The apparent rate constants (kQ) for the fluorescence quenching were determined by Stern–Volmer plots. The plots of kQ vs the free-energy changes for the electron transfer from 1 to the excited singlet of Fl showed the Rehm–Weller-type correlation. However, plots for H2O/SDS were deviated from a curve calculated by the Rehm–Weller equation, although plots for MeCN were fitted to the calculated curve. The deviation in H2O/SDS is attributable to the incorporation of Fl and 1 into the hydrophobic domain of the SDS micelle, where the condensation, less-polar medium, and exteior negative charge operate favorably for efficient electron transfer.