Water Helicity-Modulated Hierarchical Inverse Chirality Transfer in Supramolecular Assembly.

Water helicity is ubiquitous in biological architectures (e.g., proteins and enzymes) and plays a crucial role in hierarchical chirality transfer. However, achieving water helicity-modulated hierarchical inverse chirality transfer (e.g., molecular chirality to water helicity and ultimately to nanoscale chirality opposite to that of water) remains a fundamental challenge, owing to the intricate coupling between water conformation and structural hierarchies. Here we demonstrate that a helical water can be constructed and mediate inverse chirality transfer by rationally designing l-phenylalanine derivative (LPPF) featuring a geometrically matched carboxyl pocket for water. A two-step inversion cascade of chirality emerges: the L-configured molecular stereocenter dictates an M-helical arrangement of water in carboxyl pocket, which in turn templates the P-helicity of LPPF nanofibers. This process only requires trace amounts of water, and its absence results in achiral nanobelts and circular dichroism (CD) silence. Besides, the helical water has a crucial influence on the function of P-nanofibers as indicative by the transformation of spin selectivity from up to down upon in situ removal of helical water. Our findings provide deeper insight into the complexity of chirality transfer by revealing a water-helicity-modulated inverse transfer mechanism.