Red luminescent helical ribbons based on a non-polar charge-transfer complex

We reported a novel donor-acceptor complex with near-infrared emission of 735 nm. During the hierarchical self-assembly process, the supramolecular system twisted into a micro-helix with red emission, depending on both crystal thickness and used solvent, despite the nonpolar structure. It is revealed that the uniform alignment of cyano groups along the stacking columns and the solvent effect induces the twisting. This research provides an innovative approach for designing helical organic micro/nanostructures and near-infrared emission materials.