Persistent room-temperature phosphorescence (p-RTP) from pure organics is attractive
due to its fundamental importance and potential applications in molecular imaging,
sensing, encryption, anticounterfeiting, etc.1-4 Recently, efforts have been also made in
obtaining color-tunable p-RTP in aromatic phosphors5 and nonconjugated polymers6,7.
The origin of color-tunable p-RTP and the rational design of such luminogens,
particularly those with explicit structure and molecular packing, remain challenging.
Noteworthily, nonconventional luminophores without significant conjugations generally
possess excitation-dependent photoluminescence (PL) because of the coexistence of
diverse clustered chromophores6,8, which strongly implicates the possibility to achieve
color-tunable p-RTP from their molecular crystals assisted by effective intermolecular
interactions. Here, inspirited by the highly stable double-helix structure and multiple
hydrogen bonds in DNA, we reported a series of nonconventional luminophores based on
hydantoin (HA), which demonstrate excitation-dependent PL and color-tunable p-RTP
from sky-blue to yellowish-green, accompanying unprecedentedly high PL and p-RTP
efficiencies of up to 87.5% and 21.8%, respectively. Meanwhile, the p-RTP emissions are
resistant to vigorous mechanical grinding, with lifetimes of up to 1.74 s. Such robust,
color-tunable and highly efficient p-RTP render the luminophores promising for varying
applications. These findings provide mechanism insights into the origin of color-tunable
p-RTP, and surely advance the exploitation of efficient nonconventional luminophores.