Bis(phenylthienyl)ethene-tethered beta-cyclodextrin dimers as photoswitchable hosts.

Two beta-cyclodextrin dimers tethered by photoswitchable bis(phenylthienyl)ethene moieties were synthesized as potentially tunable receptor molecules. The cyclodextrin cavities of these dimers were linked via their secondary sides, with the photochromic bis(phenylthienyl)ethene unit either directly connected to the secondary rim (7) or via propyl spacers (10). By irradiation with light the dimers were reversibly switched between a relatively flexible (open) form and a rigid (closed) form.

Photocontrolled release and uptake of a porphyrin guest by dithienylethene-tethered beta-cyclodextrin host dimers.

Two photoswitchable dithienylethene-tethered beta-cyclodextrin dimers were synthesized to function as host molecules with an externally controllable binding affinity. The cyclodextrin cavities of these dimers are linked through their secondary sides by a photochromic dithienylethene unit that is connected to the secondary rim either directly (4) or through propyl spacers (9). Irradiation with light switches these dimers between a relatively flexible (open) and a rigid (closed) form.

A dithienylethene-tethered beta-cyclodextrin dimer as a photoswitchable host.

The binding of TSPP by a dithienylethene-tethered beta-cyclodextrin dimer can be altered reversibly by irradiation with light.