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An efficient indolo[3,2,1-jk]carbazole-fused MR-TADF emitter with a B/N skeleton exhibits a considerable reverse intersystem crossing rate and the corresponding organic light-emitting diode displays an external quantum efficiency of 27.2% with suppressed efficiency roll-off.

Two phenoxazine fused MR-TADF materials based on a B/N framework show high PLQYs and small FWHMs in toluene solutions, while their OLEDs exhibit EQEs of up to 21.3% with small efficiency roll-offs and narrow EL emissions.

Herein, we report two multiple-resonance thermally activated delayed fluorescence emitters (VTCzBN and TCz-VTCzBN) based on indolo[3,2,1-jk]carbazole unit and boron-nitrogen skeletons, whose emissions peaking at 496 and 521 nm with full width at half maximum of 34 and 29 nm, respectively. Meanwhile, fast rate constants of reverse intersystem crossing of above 10

The realization of luminescent materials with narrowband and circularly polarized luminescence (CPL) is of great significance for the development of future optical and photonic devices. Herein, through a steric-hindrance-assisted dual-core strategy, two pairs of chiral dual-core multiple resonance thermally activated delayed fluorescence (MR-TADF) materials (R/S-DOBN and R/S-DOBNT) are directly constructed by the bonding of two organoboron MR-TADF monocores (SOBN and SOBNT) with carbazole/3,6-di-tert-butyl-9H-carbazole and phenol derivative as donors, realizing obvious CPL and narrowband emissions. Furthermore, the dual-core effect in the prepared R/S-DOBN and R/S-DOBNT increases the transition oscillator strength two times more than that of a monocore structure, while maintaining the ultrapure blue emissions peaking at 453 and 459 nm with a narrower full-width at half-maximum of 21 nm through reorganization energy reduction. The circularly polarized organic light-emitting diodes based on the enantiomers exhibit ultrapure blue emission with Commission Internationale de L'Eclairage (CIE) coordinates of (0.14, 0.10) and (0.13, 0.12), high maximum external quantum efficiencies of 23.9% and 25.6%, and obvious circularly polarized electroluminescence with dissymmetry factors (|g

Two new organic–inorganic hybrid sodium halides based on the piperazinediium dication have been synthesized, with C4H12N2·NaI3 presenting a three-dimensional perovskite structure and 3C4H12N2·NaI4·3I·H2O showing a three-dimensional hydrogen-bonded supra­molecular network., The rational selection of ligands is vitally important in the construction of new organic–inorganic hybrid three-dimensional perovskite complexes. As part of an exploration of perovskite-type materials, two new Na–I compounds based on the piperazine ligand, namely poly[piperazinediium [tri-μ-iodido-sodium]], {(C4H12N2)[NaI3]}n, 1, and catena-poly[tris­(piperazinediium) [[tri­iodido­sodium]-μ-iodido] triiodide monohydrate], {(C4H12N2)3[NaI4]I3·H2O}n, 2, have been synthesized by adjusting the stoichiometric ratio of sodium iodide and piperazine, and were characterized by single-crystal X-ray diffraction. In the crystal structures of 1 and 2, each NaI cation is linked to six I atoms, but the compounds show completely different configurations. In 1, the structure includes a perovskite-like array of vertex-sharing NaI6 octa­hedra stretching along the direction of the three axes, and each piperazinediium dication is enclosed in the NaI3 perovskite cage. However, in 2, each NaI atom bridges a single I atom to form a one-dimensional linear chain, and complex inter­molecular hydrogen bonds connect these one-dimensional chains into a three-dimensional supra­molecular network.