Switching the Interior Hydrophobicity of a Self-Assembled Spherical Complex through the Photoisomerization of Confined Azobenzene Chromophores


  • This research was supported by the CREST project of the Japan Science and Technology Agency (JST), for which M.F. is the principal investigator, and partially by the Ministry of Education, Culture, Sports, Science and Technology of Japan. This work has been performed under the approval of the Photon Factory Program Advisory Committee (Proposal No. 2006G284). We thank Dr. M. Kawano for the synchrotron X-ray study.


original image

Synergy effect: A discrete highly cationic spherical Pd12L24 complex was prepared that concentrates 24 photoresponsive azobenzene units internally (see picture; shell blue, N dark blue, Pd yellow, O red, C gray, H white; azobenzene units shown as CPK models). The concentrated azobenzenes provide a hydrophobic environment in the sphere, and the degree of hydrophobicity is reversibly changed by the isomerization of the azobenzenes.