Color-Tunable Circularly Polarized Room-Temperature Phosphorescence by Intermolecular Phosphorescence Resonance Energy Transfer in a Chiral Co-assembled Liquid Crystal Polymer Network

Circularly polarized room-temperature phosphorescent (CP-RTP) materials have been attracting great attention due to their potential applications in anticounterfeiting. In this study, we designed and synthesized a host-guest copolymer (<b>PBXT</b>) with strong phosphorescence emission and a long emission lifetime using a self-doping strategy. The co-assembled liquid crystal polymer networks <b>(LCPNs)</b>_{<b><i>x</i></b>}<b>-(</b><i><b>R</b></i>_<b>I</b>/<i><b>S</b></i>_<b>I</b><b>)</b>_{<b><i>y</i></b>} doped with <b>PBXT</b> demonstrated a stronger RTP emission and longer lifetime (τ = 148 ms). Among them, <b>(LCPNs)</b>_<b>0.91</b><b>-(</b><i><b>R</b></i>_<b>I</b><b>)</b>_<b>0.09</b> showed strong CP-RTP signals (|<i>g</i>_RTP| = 0.071) through chiral supramolecular co-assembly. By dropping Nile Red (<b>NR</b>) into <b>(LCPNs)</b>_<b>0.91</b><b>-(</b><i><b>R</b></i>_<b>I</b>/<i><b>S</b></i>_<b>I</b><b>)</b>_<b>0.09</b>, the resulting <b>[(LCPNs)</b>_<b>0.91</b><b>-(</b><i><b>R</b></i>_<b>I</b>/<i><b>S</b></i>_<b>I</b><b>)</b>_<b>0.09</b><b>]</b>_{<b>0.9925</b>}<b>-(NR)</b>_{<b>0.0075</b>} emitted intense red circularly polarized luminescence (CPL) of <b>NR</b> dye (λ_em = 636 nm and |<i>g</i>_em| = 0.073) with a long lifetime (τ = 26 ms) under the regulation of an intermolecular phosphorescence resonance energy transfer (PRET) mechanism. Additionally, <b>[(LCPNs)</b>_{<b><i>x</i></b>}<b>-(</b><i><b>R</b></i>_<b>I</b>/<i><b>S</b></i>_<b>I</b><b>)</b>_{<b><i>y</i></b>}<b>]</b>_{<b><i>m</i></b>}<b>-(NR)</b>_{<b><i>n</i></b>} has been explored for applications in time-varying information encryption and quadruplex anticounterfeiting information encryption through the PRET progress.