Frontiers in chiral phosphorescent complexes for circularly polarized electroluminescence

Abstract

Chiral phosphorescent metal complexes always show outstanding CP-OLED performances. But unfortunately, the dissymmetry g factors are only at the 10−4–10−2 level. A balance between these two elements is the main point for future work in this area.

Circularly Polarized Luminescence of Cyclometalated Platinum(II) Complex Excimers: Large Difference between Isomers

“…Many papers studying the CPL spectra of organic and inorganic materials have been published from many laboratories. , Aggregation-induced luminescence and CPL have recently attracted considerable attention in the field of organic and coordination chemistry. − A large enhancement of the CPL signal in polymer materials has also been reported. , Especially, many papers studying CPL of platinum­(II) complexes have been published in recent years. − They also include enhancement of CPL signals via aggregation-related phenomena − and device-oriented works. ,− However, few studies have been carried out to evaluate the CPL of excimers or exciplexes . Recently, to the best of our knowledge, only one study has reported the enhancement of the intensity of the CPL signal due to chiral excimer formation based on platinum­(II) complexes in solution.…”

“…trans-[Pt(ppy)(D-pbc)] was obtained from the later eluted fractions 1. H NMR (CD 2 Cl 2 , 500 MHz): δ 8.95 (br, dd, 1H, J = 0.7, 5.0 Hz), 7.87 (dt, 1H, J = 1.6, 6.4 Hz), 7.67 (d, 1H, J = 8.0 Hz), 7.56 (dd, 1H, J = 1.4, 6.2 Hz), 7.42 (br, dd, 1H, J = 1.2, 6.6 Hz), 7.17 (m, 2H), 7.10 (dt, 1H, J = 1 43,. 6.16 Hz), 2.99 (m, 1H), 2.11 (m, 1H), 1.68 (m, 1H), 1.45 (m, 2H), 1.16 (s, 3H), 0.95 (s, 3H), 0.85 (s, 3H).…”

Electrically Amplified Circularly Polarized Luminescence by a Chiral Anion Strategy

“…It is established that the working mechanism of LECs with iTMCs is dependent on the mobile metal cations and counteranions in the active layer [11b, 13] . Considering that the CS − anions are much smaller in size than the Ir III and Ru II cations, these chiral anions tend to redistribute and accumulate near the electrodes when a voltage is applied.…”

Chiral hybrid manganese(ii) halide clusters with circularly polarized luminescence for X-ray imaging

“…Materials with circularly polarized luminescence (CPL) have attracted widespread attention due to their wide potential applications for 3D displays, optical data storage, photoelectric devices, asymmetric synthesis, and so on. 1–19 In general, the degree of circular polarization is defined by the strength of left and right circularly polarized light ( I L and I R ). 20 In order to effectively evaluate the intrinsic properties of CPL materials, the luminescence dissymmetry factor ( g lum ) is defined as the difference between the strength of I L and I R divided by their average total luminescence strength, namely g lum = 2 × ( I L − I R )/( I L + I R ).…”