Tetraphenylcyclopentadiene-Based Hyperbranched Polymers: Convenient Syntheses from One Pot “A4 + B2” Polymerization and High External Quantum Yields up to 9.74% in OLED Devices

Advances in the application of named reactions in polymer synthesis

With the development of polymer science, more and more named reactions have been applied to synthesizing polymers. Introducing new reactions into polymer synthesis is undoubtedly an excellent expansion for monomer and polymer libraries. In this review, the named reactions employed in polymer-chain synthesis were divided into seven types: electrophilic reactions, nucleophilic reactions, transition metal-mediated cross-coupling reactions, free radical reactions, pericyclic reactions, multi-component reactions and rearrangement reactions. The discussion was mainly focused on the progress in the utilization of these named reactions in polymer synthesis, which could be a valuable reference for researchers in the polymer field.

Tetradentate Pt(II) Complexes with Peripheral Hindrances for Highly Efficient Solution-Processed Blue Phosphorescent OLEDs

Two tetradentate Pt(II) complexes with peripheral bulky-group hindrances [Pt(pzpyOczpy-B1) and Pt(pzpyOczpy-B2)] were synthesized and fully investigated for their structural and blue phosphorescent properties. Both X-ray crystallography and computational simulation revealed that bulky substituents incorporated into the C-pyrazolyl and C-pyridinyl positions lie out of the cyclometallated plane, thus alleviating the intramolecular distortions as well as reducing the intermolecular interaction in the solid state. In dichloromethane, their emission peaks at 460 nm with a narrow full width at half-maximum (FWHM) of less than 50 nm, and the photoluminescent quantum yields are over 95% with short decay lifetimes (<5 μs). Solution-processed blue devices are fabricated based on the two complexes. Device A based on Pt(pzpyOczpy-B1) shows excellent electroluminescent performances with the maximum current efficiency, power efficiency, and external quantum efficiency of 47.0 cd/A, 24.6 lm/W, and 22.9%, respectively. The understanding on inert peripheral hindrances provides an effective approach to designing Pt(II) complexes for high-quality blue phosphorescent emitters.

Solution-Processable Chiral Boron Complexes for Circularly Polarized Red Thermally Activated Delayed Fluorescent Devices

Circularly polarized luminescence (CPL) molecules, especially those with thermally activated delayed fluorescence (TADF) properties, have attracted considerable attention due to their great potential for chiroptical organic light emitting diode (OLED) devices. Here we developed a new pair of TADF emitters with CPL based on boron complexes using chiral donor (cD) binaphthalene, acceptor (A) biphenyl boron β-diketonate, and donor (D) biphenylamine in a cD-A-D architecture. With this design, both efficient intramolecular charge transfer (ICT) and chiral ICT for high-performance CPL were established, leading to high dissymmetry factors (|g_lum|) up to 2.2 × 10^-3 in solution and significantly red-shifted emission around 600 nm for red TADF with a quantum yield over 15% in doped films. More impressively, with these chiral TADF emitters, solution-processed red circularly polarized OLEDs (CP-OLEDs) exhibit external quantum efficiencies (EQEs) up to 2.0% and efficient circularly polarized electroluminescence with dissymmetry factors of 2.6 × 10^-3, which are among the best performances of the reported solution-processed orange-red and red TADF CP-OLEDs. These results illustrate the great success of the cD-A-D strategy in designing high-performance CPL TADF emitters with axially chiral boron complexes, providing important clues to understand efficient chiral transfer for large |g_lum| values and high device performance of CP-OLEDs.

Synthesis of conjugated polymers via cyclopentannulation reaction: promising materials for iodine adsorption

A new class of conjugated polymers is prepared by means of a versatile palladium-catalyzed cyclopentannulation reaction using a series of specially designed diethynyl aryl synthons with the commercially available 9,10-dibromoanthracene DBA monomer.

AIE-active polysulfates via a sulfur(vi) fluoride exchange (SuFEx) click reaction and investigation of their two-photon fluorescence and cyanide detection in water and in living cells

Three polysulfates P1, P2 and P3 containing two representative AIE-active groups, tetraphenyl ethylene and naphthylamide, were successfully synthesized based on a sulfur(vi) fluoride exchange (SuFEx) click reaction.