Angew. Chem. Int. Ed. https://doi.org/10.1002/anie.201814624 (2019)

A gemini amphiphile is a molecule composed of two identical amphiphilic units separated by an organic spacer. At high concentration, gemini amphiphiles tend to self-assemble into nanostructured geometries which have been used for applications such as catalysis and separation. Now, Nishioka et al. have shown that aromatic gemini amphiphiles can form monodisperse micelles.

Credit: Wiley-VCH

The researchers first synthesize a V-shaped amphiphile composed of polyaromatic molecules and hydrophilic side groups. They use a linear acetylene spacer to complete the gemini. Because of their bent shape, these gemini amphiphiles do not aggregate into columnar structures like previous ones; rather, driven by π–π stacking among the aromatic components and hydrophobic interactions, they form micelles with controlled size and atomic composition. The micelles are composed of four gemini molecules and are ellipsoidal in shape, with dimensions between 2.7 nm and 1.9 nm. They form hydrophobic cavities about 2 nm in diameter. As a proof-of-principle application, Nishioka et al. show that they can efficiently incorporate organic compounds, including two C60 molecules.