Atomic-Scale Regulation of Covalent Bonding for Blue Phosphorescence.

It is a long-standing challenge to construct blue room-temperature phosphorescence (RTP) materials due to the inevitable intermolecular conjugation and red-shifted emission of chromophores. In this work, layered double hydroxides (LDHs) are employed to confine the boronic acid-containing chromophores and modulate the competitive covalent reactions between chromophores to achieve blue RTP materials. Interestingly, the self-condensation of chromophores and co-condensation between chromophore-LDHs can be effectively altered by tuning the atomically dispersed trivalent metals in the LDHs. Accordingly, blue emissive and dynamic phosphorescence from blue to cyan are achieved. The as-prepared RTP materials are successfully applied for the multi-level anti-counterfeiting. The developed strategy can provide a deep understanding of the regulation of the competitive reaction and molecular arrangement of chromophores. It is anticipated that this approach can be further extended for diverse reaction regulation and molecular engineering for the multi-functional RTP materials.