Circularly Polarized Luminescence Switching in Small Organic Molecules

Abstract

The circularly polarized luminescence (CPL) switching is of significant interest for applications in security technologies and sensing devices. Small organic molecules (SOMs) show severala dvantages over metal complexes, supramolecular assemblies, and polymers. Therefore, the recent progress on the CPL switching in SOMs is here reviewed. The resultsa re summarized based on the strategies used to tune factors that influence the emission properties, and thus, to realize CPL switching. The strategies that have been adopted include promoting the excimer formation of fluorescent units, changing the conformation of fluorophores,t uning the electronic structure of the p-skeleton/ substituent, and modulating the intramolecular chargetransfer dynamics.[a] J.

The Progress and Perspective of Organic Molecules With Switchable Circularly Polarized Luminescence

“…Though there have been some recent partial reviews (Ma J. L. et al, 2019;Sang et al, 2019), CPL emitters whose emission is switchable under various stimuli have not been comprehensively reviewed. To fill this gap, a review of switchable CPL behavior is presented herein, including the use of irradiation with light, host-guest interaction, metal ions, pH, temperature, and solvents as stimuli.…”

Thermally activated delayed fluorescence material-sensitized helicene enantiomer-based OLEDs: a new strategy for improving the efficiency of circularly polarized electroluminescence

“…Especially, CP-OLEDs based on chiral fluorescent emitters could not only successfully achieve the CPEL [17][18][19], but also have the advantages of long device lifetime, good stability and low efficiency roll-off. Moreover, chiral fluorescent molecules with CPL activities are also cheap and easily available [20][21][22][23]. However, the devices based on fluorescent emitters generally suffer low efficiencies for only 25% exciton utilization of the fluorophores (Fig.…”

“…Benefitting from the good luminescent properties and the chirality in the excited state, the enantiomers exhibited perfect mirror-image CPL signals with the g lum values of −5.9 × 10 −3 for (P)-HAI and +6.2 × 10 −3 for (M)-HAI, respectively. The g lum values of the enantiomers with rigid helical skeleton are larger than those of the most chiral luminophores with other chiral elements [20,21]. Therefore, the helicene enantiomers might be excellent chiral emitter candidates for CP-OLEDs with intense CPEL activities.…”

Chiral‐at‐Metal BODIPY‐Based Iridium(III) Complexes: Synthesis and Luminescence Properties

“…Circularly polarized emission (CPL) is rarely observed in systems different from chiral organic molecules [ 15 ] and lanthanide complexes. [ 16 ] To the best of our knowledge, studies searching for CPL in chiral‐at‐metal BODIPY containing molecules has not been reported.…”