Formation of stimuli-responsive cyclophanes by self-assembly: the case of carbazole-based biradicals

Abstract

Dynamic covalent bonds has recently received lot of attention because of their unique feature to become reversible under mild conditions.[1] In this context, π-conjugated biradical compounds has emerged as essential building blocks.[2] For instance, we have demonstrated that 2,7-dicyanomethylene-9-(2-ethylhexyl)carbazole biradical reversibly converts to a macrocycle cyclophane upon soft stimuli (temperature, pressure, light), showing strong chromic effects.[3] We now extent this study towards longer conjugated carbazole backbone (i.e., indolocarbazole shown in Figure 1), aiming at investigating how the elongation of the conjugated backbone impacts on the formation of stimuli-responsive cyclophanes. The self-assembly process is investigated both in solution and solid state by linking theory and experiments.