Dual Role of Boronic Acid Modification in Enhancing Rheological and Photophysical Properties of Supramolecular Gels

Journal article, 2024

Supramolecular gels derived from functionalized gelators offer diverse applications, and modifying the properties of existing organogels using guest molecules presents an attractive approach for designing functional gel materials with targeted properties. In this study, we investigated a method to enhance the mechanical and photophysical properties of readily prepared low molecular weight gels (LMWGs) through the incorporation of boronic acid derivatives. The leveraging of dynamic covalent bonding interactions between the hydroxyl groups of oxotriphenylhexanoates (OTHO) gelator and the boronic acid derivatives gave rise to a boronate adduct along with enhanced intermolecular aromatic stacking interactions between gelators and thereby reinforced the rheological and thermal stability of the doped OTHO gels. In an effort to probe the aforementioned aromatic interactions, we used a pyrene boronic acid dopant, which revealed that the spatial proximity between the aromatic groups of the boronic acid was close enough to display excimer formation. Our findings provide valuable insights into the regulation of mechanical strength, self-healing ability, and photophysical properties of supramolecular gels. Furthermore, this approach holds promise for broad applications in hydroxyl-containing LMWGs, enabling the development of functional gel materials with enhanced properties.