Stimuli Responsiveness Of Cyanostilbene-Based Supramolecular Polymers

Supramolecular polymers are long-range self-assembled structures formed spontaneously by monomers with functionality≥2 through high binding strength and directional intermolecular non-covalent interactions.By changing the external environment of the self-assembly system,the intermolecular non-covalent interactions can be affected,and the system can assemble into ordered molecular aggregates with special structure and function.This method is widely used in the fields of material science,biomedical science,energy and other areas due to the mild conditions and easy process monitoring.It is one of the important sources of advanced concepts and high technologies.Among the common building blocks of supramolecular assemblies,π-conjugated molecules are the basic structural units for constructing organic optical,electrical,and magnetic materials.Their delocalizedπ-bonds endow them with inherent π-π stacking ability,which significantly affects the performance of optoelectronic devices.As a novel building blocks,the structure of cyanostilbene unit is easy to modify and has excellent luminescence properties,so that changes in spectroscopic properties can be monitored to study its supramolecular polymerization behavior.Based on this,this article consists of following two parts:In the first part,we modified hydrogen bond recognition elements such as amides or ureas on the periphery of the cyanovinylstyrene unit to prepare two structurally similar monomer compounds,achieving selective control over their photochemical reactions.Both types of monomeric molecules can construct supramolecular polymers through the highly efficient addition of intermolecular hydrogen bonds and π-π stacking forces with a biomimetic "nucleation-elongation"mechanism.Based on this,we studied the photochemical reaction behaviors of the two molecules in their monomeric and assembled states.Upon 430 nm light irradiation,the solutions of the assembled state and monomeric state showed different photochemical reaction behaviors.In addition,the study showed that the small structural differences between urea and amide recognition elements can cause significant changes in the properties of supramolecular polymers,such as their thermal stability and Gibbs free energy release.These research results help to grasp the method of controlling photochemical reactions by supramolecular polymerization strategies and provide new ideas for efficient control of multi-path photochemical reactions.In the second part,we modified the peripheral cyanine-based phenylethene units with dimethylamino groups and successfully synthesized a monomer with carbon dioxide responsiveness.Building on this foundation,we induced the chiral signal in situ through the co-assembly of molecules with 5’-triphosphate adenosine(ATP).These findings provide new avenues for the development of novel intelligent chiral materials.