Mechanoresponsive Diacetylenes and Polydiacetylenes: Novel Polymerization and Chromatic Functions

Abstract This review focuses on recent advancements regarding mechanoresponsive functions of diacetylene (DA) and polydiacetylene (PDA). Their ability to undergo pronounced topochemical polymerization and chromatic behavior variations in response to external stimuli has marked them as a promising platform for chemo- and bio-sensing over the past few decades. Notably, major advances, showcasing selective and highly sensitive mechanoresponses along with their quantitative analysis, have been achieved in recent years. The categorization includes DAs undergoing pressure-controlled crystalline transitions and polymerization, as well as PDAs exhibiting mechanochromic or mechanofluorochromic transitions. Accordingly, this review covers molecular designs allowing mechanical activation for topochemical polymerization, nanostructured or hybridized PDAs for amplifying stimulus-optical response feedback, nanoscopic analytical tools for mechanochromism, and their potential applications in mechanochemical sensing and imaging.