Rational design of metal-free organic chromophores to form efficient room temperature persistent luminescent molecular crystals via H-bond-directed supramolecular self-assembly

Long-lived room temperature ‘phosphorescence’ from organic molecular crystals has attracted great attention owing to potential applications in organic electronics, information storage, and biotechnologies. The features of the persistent luminescence strongly depend on the electronic properties of the individual molecules, and on their molecular packing in the crystal lattice. Here, a new strategy is developed by rationally designing phosphors incorporating and combining for the first time a bridge for sigma-conjugation and a moiety for H-bond-directed supramolecular self-assembly. The molecular crystals exhibit room temperature ‘phosphorescence’ quantum yields that reach up to 20% and lifetimes up to 520 ms. This study provides a promising strategy for the development of molecular crystals exhibiting efficient long-lived room temperature persistent luminescence.