Steric Barrier-Steered Reaction Sites in Micellar Catalysis

In the pursuit of an advanced micellar catalysis system, the reaction sites in micelles determine its catalytic performances. However, the intrinsic polarity gradient of micelles anchors the reactants in the fixed regions, leading to an unmet challenge to steer the reaction sites to the optimal ones. To overcome this limitation, a Forster resonance energy transfer (FRET) spectroscopic ruler is established to position the true sites of reactants in micellar catalysis by using tetraphenylethylene (TPE) in the aggregation-induced emission (AIE) micelles as the FRET donor and Nile red as the FRET acceptor. Subsequently, the customizable TPE steric barriers in the AIE micelles are apt to mediate the reactants into the polar micellar surface, the semipolar palisade layer, or the nonpolar internal layer, achieving the corresponding catalytic efficiencies. Additionally, the universality of steric barrier-steered reaction sites in micellar catalysis is further demonstrated by the simple incorporation of small nonpolar molecules into the commercially available surfactants. To the authors' knowledge, this is the first report on the design of steric barriers to steer the reaction sites in micellar catalysis. These findings open up attractive perspectives for the exploration of new classes of efficient micellar catalysis systems in a variety of reactions.

Automated summary

Researchers have developed a Forster resonance energy transfer (FRET) spectroscopic ruler to locate the true sites of reactants in micellar catalysis. By using tetraphenylethylene (TPE) in aggregation-induced emission (AIE) micelles as the FRET donor and Nile red as the FRET acceptor, the TPE steric barriers can be positioned in different locations in the AIE micelles, achieving corresponding catalytic effects. The universality of steric barrier-steered reaction sites in micellar catalysis is further demonstrated by incorporating small nonpolar molecules into commercially available surfactants. These findings open up attractive perspectives for the exploration of new classes of efficient micellar catalysis systems in a variety of reactions.