Aspect Ratio-Dependent Twisting Motions in Photomechanical Molecular Crystal Ribbons via Solid-State [2 + 2] Photodimerization

Abstract

Dynamic single-crystal ribbons based on a photoactive divinylphenyl derivative (MCPD) exhibit aspect ratio-(δ, defined as length-to-width ratio)-dependent twisting motions under visible light irradiation. This crystal twisting is driven by solid-state [2 + 2] photodimerization, which can enable a single-crystal-to-single-crystal (SCSC) transformation in high-aspect-ratio ribbons and generate single crystals of photodimer.