Temperature Gating of the Ring‐Opening Process in Diarylethene Molecular Switches

The ring-opening process in diarylethene molecular switches is suppressed with decreasing temperature, leading to the complete absence of the photoreaction below a cutoff temperature. By contrast, the reverse ring-closure process shows no significant temperature dependence above 115 K. Reversibility of the photoprocesses can be thus controlled by temperature (see figure).