Dual-Responsive Thermally Activated Delayed Fluorescence of Spiropyran Derivatives

For the first time, a series of photochromic dyes SP1-3 with dual-responsive thermally activated delayed fluorescence (TADF) characteristics were reported in this research. Benefitting from the reversible light-responsive property of SP1-3, the eigen TADF of these compounds could be regulated between 588 and 678 nm or turned on/off by different wavelengths of light irradiation in a polyvinylpyrrolidone (PVP) matrix. The emission lifetime of the spiropyran derivative was prolonged to millisecond level for the first time. Moreover, the delayed fluorescence of SP1 and SP3 could also be manipulated by mechanical force because of the mechanochromistic properties of SP1 and SP3. This research is a significant breakthrough for photochromic materials and may broaden its scope. [GRAPHICS]