Secondary‐Rim γ‐Cyclodextrin Functionalization to Conjugate with C₆₀: Improved Efficacy as a Photosensitizer

Abstract

DIBAL-H-mediated demethylation provides a novel method to access secondary-rim functionalized γ-cyclodextrin. 2^A ,3^B -Dihydroxyl-per-O-methylated-γ-cyclodextrin has been obtained, whose conjugation with C₆₀ allows access to the most water-soluble C₆₀ conjugate described so far. The water solubility of 0.12 m (550 mg mL^-1 ) is 150 times higher than that of the native γ-CD/C₆₀ complex. Its singlet oxygen (¹ O₂ ) quantum yield is 0.39, an increase of one to two orders of magnitude compared to that of α(β)CD-C₆₀ conjugates.