Properties and Applications of Stimuli-Responsive Diacetylenes

The topochemical reactivity of diacetylene monomers has long been established and involves the 1,4-addition polymerization reaction. This reaction is governed by well-defined parameters that allow the synthesis of diacetylene polymers. Polydiacetylenes are conjugated polymers that display unique colorimetric and fluorescent transitions when they are exposed to a range of stimuli, allowing them to be easily exploited in biosensors, chemosensors, and radiochromic dosimeters. In this review, we summarize recent work on polydiacetylene systems, focusing on examples involving 10,12-pentacosadiynoic acid (PCDA) that can be structured as polymerized vesicles, films, gels, and powders. Synthetic derivatives of PCDA are also reviewed, along with the effect of incorporating guest molecules to a diacetylene system and establishing the important relationship between reversible thermochromism and noncovalent interactions.