A Highly Efficient Silole-Containing Dithienylethene with Excellent Thermal Stability and Fatigue Resistance: A Promising Candidate for Optical Memory Storage Materials

Diarylethene
compounds are potential candidates for applications
in optical memory storage systems and photoswitchable molecular devices;
however, they usually show low photocycloreversion quantum yields,
which result in ineffective erasure processes. Here, we present the
first highly efficient photochromic silole-containing dithienylethene
with excellent thermal stability and fatigue resistance. The photochemical
quantum yields for photocyclization and photocycloreversion of the
compound are found to be high and comparable to each other; the latter
of which is rarely found in diarylethene compounds. These would give
rise to highly efficient photoswitchable material with effective writing
and erasure processes. Incorporation of the silole moiety as a photochromic
dithienylethene backbone also was demonstrated to enhance the thermal
stability of the closed form, in which the thermal backward reaction
to the open form was found to be negligible even at 100 °C, which
leads to a promising candidate for use as photoswitchable materials
and optical memory storage.