Enhanced Piezoelectric Response via Transient Heterochiral Solvent-Solute Matching in Supramolecular Assembly.

Abstract

Chirality plays an important role in directing the piezoelectric response in self-powered next-generation electronic microdevices. However, the impact of stereoselective solvent-solute interaction on piezoelectric performance remains poorly understood. Herein, we report a heterochiral solvent-solute matching strategy for enhancing the piezoelectricity of supramolecular nanostructures assembled from enantiomeric phenylalanine derivatives, (S)-AD or (R)-AD. Piezoelectric output is strongly dependent on solvent chirality: The heterochiral (S)-CPA produces an even greater enhancement of 200% compared to homochiral solvent (R)-CPA. Time-resolved studies and molecular dynamics (MD) simulations reveal that the chiral solvent transiently engages (S)-AD at the initial assembly stage and then progressively disengages as assembly proceeds. Spectroscopic studies and density functional theory (DFT) suggest that conformation of (S)-AD undergoes a permanent change after this process, and the favorable conformation with higher molecular dipole moment is achieved via heterochiral (R)-CPA. This work establishes a heterochiral matching strategy via solvent-solute chiral recognition to amplify electromechanical coupling, providing a paradigm for designing high-performance organic piezoelectrics.