Double self-inclusion by rotating glucopyranose units in per-O-methylated β-cyclodextrin moieties attached to a porphyrin in aqueous solution

Double self-inclusion of the porphyrin part by two per-O-methylated P-cyclodextrin moieties, which were attached to the 4-positions of the phenyl groups of 10,20-bis(3,5-dicarboxylatophenyl)-5,15-diphenylporphyrin, occurred through 360degrees rotation of two glucopyranose units in the per-O-methylated cyclodextrin moieties. The self-inclusion proceeded quantitatively in aqueous solution. As the porphyrin ring was completely covered by two cyclodextrin moieties, no fluorescence quenching of the porphyrin by 9,10-anthraquinone-2-sulfonate took place. The intramolecular self-inclusion is achieved by destroying a hydrogen-bond belt at the secondary OH group side of the native cyclodextrin by O-methylation and extremely strong hydrophobic effects resulting from complexation of the porphyrin with per-O-methylated beta-cyclodextrin. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).