Self-Assembly of Fullerene-Based Janus Particles in Solution: Effects of Molecular Architecture and Solvent

Two molecular Janus particles based on amphiphilic [60]fullerene (C-60) derivatives were designed and synthesized by using the regioselective Bingel-Hirsh reaction and the click reaction. These particles contain carboxylic acid functional groups, a hydrophilic fullerene (AC(60)), and a hydrophobic C-60 in different ratios and have distinct molecular architectures: 1:1 (AC(60)-C-60) and 1: 2 (AC(60)-2C(60)). These molecular Janus particles can self-assemble in solution to form aggregates with various types of micellar morphology. Whereas vesicular morphology was observed for both AC(60)-C-60 and AC(60)-2C(60) in tetrahydrofuran, in a mixture of N,N-dimethylformamide (DMF)/water, spherical micelles and cylindrical micelles were observed for AC(60)-C-60 and AC(60)-2C(60), respectively. A mechanism of formation was tentatively proposed based on the effects of molecular architecture and solvent polarity on self-assembly.