Themed collection Circularly Polarised Luminescence

Guest editors Jeanne Crassous, Lorenzo Di Bari, Wai-Yeung Wong and You-Xuan Zheng introduce this themed collection on circularly polarized luminescence.

Metal halide perovskites (MHPs) have emerged as highly appealing materials for circularly polarized luminescence (CPL) related applications, owing to their spin-related photoelectric properties and flexible structural adjustment.

This perspective discusses the synthesis and (chir)optical properties of compact luminophores derived from [2.2]paracyclophane useful as building blocks for the development of CPL emitters.

Fibrous morphologies are ideal carriers for achiral fluorescent molecules to achieve CPL. Examples and underlying mechanisms of chirality transfer, amplification, and reversion at the single- and multiple-fiber levels are presented in this review.

The recent advances and future perspectives on circularly polarized luminescence materials based on optically active helical polymers are reviewed and discussed.

Using zinc-chlorin, the switching of MCPL/CPL via J-aggregation has been clearly demonstrated for the first time.

Circularly polarized luminescent chiral organogels based on fluorescence resonance energy transfer are fabricated by supramolecular co-assembly in an achiral polymer system, in which a wavelength shift and amplified g_lum are achieved.

Bacterial cellulose (BC)-based wave plates with tunable phase delays for polarization-encryption applications.

Using the chiral [Sm(tta)₃(D-phen)] as emitter, the first example of chiral organo-Ln³⁺-based CP-WOLED with both attractive white-light efficiencies (η^Max_EQE = 1.55% and η^Max_CE = 1.61 cd A⁻¹) and high dissymmetry factor (|g_EL|^Max = 0.011) is reported.

A new donor–acceptor type circularly polarized luminescence material has been developed, and a dihedral angle engineering strategy has been demonstrated for the first time to significantly amplify the luminescence dissymmetry factors.

Modulating the helical pitch by simply playing with steric effects in a series of helically flexible BODIPY dimers allows easy tuning of the luminescence dissymmetry factors associated with their circularly polarized emissions.

We prove the relationship between the cross-section radius and polarization ratio, and demonstrate the maximum polarization ratio is about 60% when the cross-section radius is 1.15 μm in a Sn-doped CdS microcone.

Probing the Chiroptical Enigma: compelling evidence calling for a re-evaluation of experimental g_lum values of two 1,1′-bitriphenylene-based [7]helicenes is obtained by TD-DFT simulations with advanced state-specific solvation effects.

Models of chiral hybrid perovskites are studied by ab initio molecular dynamics, projected density of states, TD-DFT and ECD spectra calculations to clarify how the chiral bias affects the inorganic octahedra and how it differs in lead and tin cases.

Field-induced single-molecule magnet behavior and circularly polarized luminescence were observed in a series of ytterbium one-dimensional coordination polymers involving chiral BINOL-derived bisphosphate ligands.

Chiral tetraarylethylene-diketopyrrolopyrroles, synthesized by a strategy involving a Mitsunobu type N-alkylation and Suzuki–Miyaura coupling, show CD and circularly polarized luminescence in solution and enhanced emission in the aggregate states.

(R-/S-Br-MBA)₃MnBr₅ shows reversible conversion of CPL emission in wavelength and direction during heating and cooling.

Efficient near-infrared circularly polarised luminescence (CPL) between 1400 and 1600 nm of four enantiomer pairs of homo- and heteroleptic complexes have been successfully measured.

Circularly polarized luminescence activity from new cationic water soluble Sm(III) and Eu(III) complexes is triggered by one- and two-photon absorption processes. The Eu(III) complex is shown to be an efficient NIR-to-RED probe in cellulo.

The materials incorporating a moderate electron-donating chiral unit (BAM) closer to the chromophore and participating in the frontier molecular orbitals distributions may achieve a balance between a large g value and high fluorescence quantum yield.

Circularly polarized organic room temperature phosphorescence (CPRTP) with g_max = +0.098 was activated by the rigid environment of an in situ cross-linked liquid crystalline polymer network.

Two pairs of enantiomorphic organic–inorganic hybrid manganese(II) halide clusters show excellent CPL properties and work as scintillators in X-ray detection and imaging.

The measured EL g factors (symbols) were fitted with a quadratic equation of the order parameter in the twisted configuration of a mesogenic conjugate polymer (F8BT) doped with various concentrations of a chiral dopant (R5011).

Chiroptical activities of Au₁₃ superatom modified with chiral ligands were enhanced by doping of an Ir atom at the center of the core. The IrAu₁₂ superatom exhibited the brighter circularly polarized luminescence than Au₁₃ superatom.

We demonstrated the aggregation-enhanced emission and circularly polarized luminescence of chiral 1,1′-bi-2-naphthol-substituted boron dipyrromethene derivatives in the red and near-infrared regions.

Mixing a chiral Cr(III) complex with an achiral Eu(III) complex into a silica nanoparticle gave rise to simultaneous unpolarized red and polarized NIR luminescence.

2D films of enantiopure stapled o-OPEs have been used to develop a CPL-barcoding system free of photoselection artifacts. The use of both enantiomers makes the system easier and safer to read.

Multicolored fluorescence, high Φ_PL reaching 59%, and an efficient g_lum up to 0.01 with the brightness for circularly polarized luminescence (125.2 M⁻¹ cm⁻¹), were achieved in axially chiral tetra-BF₂ complexes by substituent engineering.

R/S-(BINAP)₂Cu(μ-I₂) enantiomer doped films show a high |g_PL| factor above 1 × 10⁻², while a pioneering work of CP-OLEDs based on chiral Cu(I) enantiomers exhibited a high EQE of 21.7% and |g_EL| factors of around 3.0 × 10⁻³.

An enhancement of stability of helicity memory, solubility, and fluorescence properties of a poly(diphenylacetylene) has been achieved through ion-pair formation.

Optical resolution of pseudo-para-disubstituted [2.2]paracyclophane was achieved by the diastereomer method. Enantiopure optically active molecules emitting circularly polarized luminescence were synthesized.

A liquid crystalline poly(para-phenylene) derivative forms a helically π-stacked structure upon addition of a chiral binaphthyl compound, exhibiting blue circularly polarized luminescence.

CPL-active microspheres and microcrystals are fabricated via the reaction and co-assembly of pyridine derivatives with a chiral phosphoric acid.

A novel europium-based hybrid material, Eu(D-facam)₃-TMAOAc (tetramethylammonium acetate), with ultra-high luminescence, excellent circular polarization and remarkable thermostability was prepared.

We fabricated stimuli-responsive solid particles with amplified circularly polarized luminescence based on a cis-transoidal helix, temperature-responsive and pH-responsive CPL properties.

The new homochiral Zn-based coordination compounds reveal excellent enantioselective sensing behavior toward D- and L-histidine attributed to the host–guest interactions through the rigid chiral backbones.

By tuning weight percentages rationally for precursor solutions, we found that large magneto-PL (−13.2%) with strong tunability via polarized photoexcitation is highly decided by crystallographic orientations for chiral perovskites.