Chirality-controlled seeded supramolecular polymerization: From glutamide amphiphiles to ultralong helical nanotubes

Self-assembled organic helical nanotubes hold great promise for mimicking the sophisticated architectures and functions of natural biological systems. However, controlling stereospecific self-assembly with high fidelity over multiple hierarchical length scales still remains a formidable challenge. We report a chirality controlled supramolecular polymerization strategy to precisely control the assembly of enantiomeric glutamide amphiphile helical nanotubes in alcoholic solvents. While short helical nanotubes form under rapid cooling, slow cooling yields twisted nanofibers. Chiral helical nanotube can serve as seed to direct the stereospecific supramolecular polymerization: homochiral seeds produce ultralong helical nanotubes with uniform diameter and aspect ratios over 1000, whereas opposite chirality leads to twisted nanofibers. The seeded growth of helical nanotube shows accelerated kinetics, living characteristics and narrowed length distribution. Moreover, the ultralong helical nanotubes enable further chiral assembly of porphyrins. This work establishes a chirality-selective seed-initiated pathway for stereospecific helical nanotube growth from molecular to hundreds-of-micrometer scales.