Programmed self-assembly of conjugated oligomer-based helical nanofibres through hydrogen bonding interactions†

Abstract

We report the synthesis and programmed self-assembly of m-phenylene vinylene (m-PPV) derivatives containing amino acid functional groups. These derivatives form highly fluorescent nanofibres through hydrogen bonding, rather than π–π stacking. Systematic investigation of tyrosine-based derivatives reveals the critical role of lateral and vertical hydrogen bonding sites in forming uniform, high-aspect-ratio nanofibres, as confirmed by cryo-TEM and SEM (diameters 2–3 nm, lengths > 20 μm). Chiral centres promoted helical nanofibres, while achiral oligomers formed straight fibres. Our study demonstrates the ability to form large-area, homogeneous straight and helical nanofibres with a high aspect ratio and increased melting point from 185 °C to 209.4 °C. Photophysical studies showed thickness-dependent fluorescence lifetimes, attributed to self-quenching. This work enhances the understanding of structure–property relationships in supramolecular assemblies and offers a new design strategy for biomimetic nanomaterials.