Constructing Mechanically Flexible Molecular Crystals with Tunable Near-Full-Spectrum Emission via an α-Cyanodiarylethene Scaffold

Abstract A series of mechanically flexible molecular single crystals based on donor–acceptor building blocks has been successfully prepared, exhibiting broadly tunable emission from sky-blue (473 nm) to red (644 nm). These single crystals exhibit either plastic or elastic deformation. Furthermore, the structural compatibility between selected members of this series facilitates molecular doping, enabling continuous fine-tuning of luminescence by adjusting the molar feed ratios. The mechanical and emissive properties render these crystals promising as lightweight, flexible, and color-tunable optical waveguides, highlighting the potential of organic crystals for flexible optoelectronic technology.