Photochromism of dithienylethene-bis(trimethylammonium) iodide in cyclodextrin cavities

Abstract

On the addition of β-cyclodextrin, the proportion of the photoactive anti-parallel conformation of photochromic 2,2′-dimethyl-3,3′-(perfluorocyclopentene-1,2-diyl)bis(benzo[b]thiophen-6-yltrimethylammonium) iodide (1a) increased, and the cyclization quantum yield was found to increase. On the other hand, the proportion of the photoinactive conformation increased on the addition of γ-cyclodextrin and the quantum yield decreased. The structures of the complexes were estimated from NOESY spectra.