Molecules That Assemble by Sound: An Application to the Instant Gelation of Stable Organic Fluids

The first molecule that assembles by ultrasound is described. An association-inert dinuclear Pd complex, anti-1a, which is stabilized by intramolecular π-stacking interactions, gelatinizes a variety of organic solvents instantly upon brief presonication for a few seconds. This is the first quick, positive, and reversible method for the remote switching of stable sol-gel phases. Uniquely, the rate can be precisely controlled over the range between “no gelation” and “instant gelation” simply by tuning the sonication time.