Fluorination-controlled supramolecular polymerization and piezoelectric behavior

This study explores the fluorine effect on the supramolecular polymerization and piezoresponse of naphthalene-diimide (NDI) derivatives. A single fluorine substitution in NDI-F induces higher crystallinity, thermal stability and cooperativity compared to its hydrogenated analogue (NDI-H). Molecular dynamics simulations reveal that aligned C-F dipoles stabilize the supramolecular polymer via C-H⋯F interactions. Consequently, NDI-F exhibits a much superior piezoelectric coefficient (d₃₃ ≈ 24 pm V^-1) than that of NDI-H.