H-Shaped Supra-AmphiphilesBased on a DynamicCovalent Bond.

The imine bond, a kind of dynamic covalent bond, is usedto bindtwo bolaform amphiphiles together with spacers, yielding H-shapedsupra-amphiphiles. Micellar aggregates formed by the self-assemblyof the H-shaped supra-amphiphiles are observed. When pH is tuned downfrom basic to slightly acidic, the benzoic imine bond can be hydrolyzed,leading to the dissociation of H-shaped supra-amphiphiles. Moreover,H-shaped supra-amphiphiles have a lower critical micelle concentrationthan their building blocks, which is very helpful in enhancing thestability of the benzoic imine bond being hydrolyzed by acid. Thesurface tension isotherms of the H-shaped supra-amphiphiles with differentspacers indicate their twisty conformation at a gas–water interface.The study of H-shaped supra-amphiphiles can enrich the family of amphiphiles,and moreover, the pH-responsiveness may make them apply to controlledor targetable drug delivery in a biological environment. [ABSTRACT FROM AUTHOR]