Anisometric C60 fullerene colloids assisted by structure-directing agent†
C60 molecular crystals are synthesized from aromatic solvents assisted by trimethylpyridine as a structure-directing agent. The nitrogen moiety associates with the faces of growing crystals and stabilizes crystal growth in the aromatic solvents, tetralin and mesitylene. Anisometric colloids with diverse morphology are produced as a function of concentration and injection volume of fullerene solutions using co-solvent precipitation with the crystal growth modifier. The microcrystals exhibit well-defined faceting, higher aspect ratios and enhanced molecular packing efficiency as determined by electron microscopy, time-resolved fluorescence spectroscopy and confocal microscopy with quantitative image analysis. Solvent–antisolvent compatibility is nontrivial for the synthesis of monodisperse colloids and our approach may enable controlled precipitation in a variety of solvent systems to obtain diverse internal crystal structures and external forms for photonic applications.