The photocyclization reactivity of an inverse type diarylethene derivative decreased by inclusion into β-cyclodextrin. From the detailed investigation using job-plots, NOESY spectra and DFT calculations, it was elucidated that this is ascribed to the restriction of the rotational motion between thiophene and phenyl rings. These results would provide useful information for the photochromic reaction dynamics of inverse type diarylethenes.

Abstract

Diarylethene derivatives are one of the promising compounds for practical applications including optical memory, display, sensor, and photoactuator. In this work, we newly designed and synthesized an inverse type diarylethene derivative bearing sodium carbonate groups at the p-position of the lateral phenyl ring and investigated the photochromic behavior in the presence and absence of cyclodextrins (CDs) (αCD, βCD, and γCD). Interestingly, only in the presence of βCD, the photocyclization reactivity decreased. From the results of job-plots, NOESY spectra, and quantum chemical calculations, it was suggested that the distinctive interaction between the diarylethene and βCD leads to the restriction of molecular geometrical change, resulting in the suppression of the photocyclization reactivity. These results provide information on the rational designing of inverse type diarylethenes with advanced properties.