Long-Persistent Circularly Polarized Luminescence from a Host-Guest System Regulated by the Multiple Roles of a Gold(I)-Carbene Motif.

The promotion of intersystem crossing (ISC) is critical for achieving a high-efficiency long-persistent luminescence (LPL) from organic materials. However, the use of a transition-metal complex for LPL materials has not been explored because it can also shorten the emission lifetime by accelerating the phosphorescence decay. Here, we report a new class of LPL materials by doping a monovalent Au-carbene complex into a boron-embedded molecular host.

Highly Efficient Au(I) Alkynyl Emitters: Thermally Activated Delayed Fluorescence and Solution-Processed OLEDs.

Two-coordinate donor-metal-acceptor type coinage metal complexes displaying efficient thermally activated delayed fluorescence (TADF) have been unveiled to be highly appealing candidates as emitters for organic light-emitting diodes (OLEDs). Herein a series of green to yellow TADF gold(I) complexes with alkynyl ligands has been developed for the first time. The complexes exhibit high photoluminescence quantum yields (PLQYs) of up to 0.

Highly Efficient Thermally Activated Delayed Fluorescence from Pyrazine-Fused Carbene Au(I) Emitters.

Metal-based thermally activated delayed fluorescence (TADF) is conceived to inherit the advantages of both phosphorescent metal complexes and purely organic TADF compounds for high-performance electroluminescence. Herein a panel of new TADF Au(I) emitters has been designed and synthesized by using carbazole and pyrazine-fused nitrogen-heterocyclic carbene (NHC) as the donor and acceptor ligands, respectively. Single-crystal X-ray structures show linear molecular shape and coplanar arrangement of the donor and acceptor with small dihedral angles of <6.

Analysis of Magneto-Mechanical Response for Magnetization-Graded Ferromagnetic Material in Magnetoelectric Laminate.

This paper analyzes the dynamic magneto-mechanical response in magnetization-graded ferromagnetic materials (MGFM) comprised of high-permeability Finemet and traditional magnetostrictive materials. The theoretical modeling of the piezomagnetic coefficient that depends on the bias magnetic field of MGFM is proposed by using the nonlinear constitutive model of a piezomagnetic material, the magnetoelectric equivalent circuit method, and the simulation software Ansoft. The theoretical variation of piezomagnetic coefficients of MGFM on the bias magnetic field is in good agreement with the experiment.

Nonlinear Magnetoelectric Response of FeCuNbSiB/Piezofiber Composite for a Pulsed Magnetic Field Sensor.

In this paper, we report the nonlinear magnetoelectric response in a homogenous magnetostrictive/piezoelectric laminate material. The proposed magnetoelectric stack FeCuNbSiB/piezofiber is made up of high-permeability magnetostrictive FeCuNbSiB foils and a piezoelectric Pb(Zr, Ti)O fiber composite. The time dependence of magnetoelectric interactions in the FeCuNbSiB/piezofiber structure driven by pulsed magnetic field was investigated in detail.

Direct Conversion of Benzothiadiazole to Benzimidazole: New Benzimidazole-Derived Metal-Organic Frameworks with Adjustable Honeycomb-Like Cavities.

Up to now, the direct conversion of the thiadiazole ring to other heterocyclic rings has been a very challenging task. Herein, a Cd -mediated alcohol-substitution strategy for direct conversion from benzothiadiazole to benzimidazole is reported. Experimental and molecular modeling studies on the role of the chelated metal ion in this in situ alcohol-substitution reaction revealed that it serves as an all-rounder that is involved in the insertion of alcohol, activation of the thiadiazole ring by coordinative interaction, and the sulfur-extrusion process.

From Surprising Solvothermal Reaction to Uncommon Zinc(II)-Catalyzed Aromatic C-H Activation Reaction for Direct Nitroquinoline Synthesis.

In this work, we first found a surprising solvothermal reaction for direct dinitration of quinoline derivative. To explore the application in direct nitroquinoline synthesis, this reaction was subsequently modified as an equivalent reaction in a Schlenk tube. More significantly, after a constant attempt, nitrated derivative was obtained in optimized condition with a zinc(II) sulfate catalyst, where some substrates with strong electron-withdrawing group were first nitrated by a directly catalyzed condition.