Construction and function of a highly efficient supramolecular luminescent system.

Aggregation-induced emission (AIE) provides a new way of achieving highly efficient luminescent materials. In this contribution, the self-assembly behavior, molecular stacking structure and photophysical properties of two polymorphs of a supramolecular co-crystal (C1 and C2) are investigated. The block-like crystal C1, packed in segregated stacking with strong π-π interactions between the H and G molecules, shows weak green emission with a low efficiency (Φ) of 2%. In comparison, the needle-like crystal C2, packed in segregated stacking with no obviously strong intermolecular interactions, shows bright yellow emission. More importantly, C1 exhibits mechanochromic behavior.