Tunable afterglow for mechanical self-monitoring 3D printing structures.

Self-monitoring materials have promising applications in structural health monitoring. However, developing organic afterglow materials for self-monitoring is a highly intriguing yet challenging task. Herein, we design two organic molecules with a twisted donor-acceptor-acceptor' configuration and achieve dual-emissive afterglow with tunable lifetimes (86.

Highly Twisted Thermally Activated Delayed Fluorescence (TADF) Molecules and Their Applications in Organic Light-Emitting Diodes (OLEDs).

Thermally activated delayed fluorescence (TADF) materials have attracted great potential in the field of organic light-emitting diodes (OLEDs). Among thousands of TADF materials, highly twisted TADF emitters have become a hotspot in recent years. Compared with traditional TADF materials, highly twisted TADF emitters tend to show multi-channel charge-transfer characters and form rigid molecular structures.

Realizing Photoswitchable Mechanoluminescence in Organic Crystals Based on Photochromism.

Organic mechanoluminescent (ML) materials possessing photophysical properties that are sensitive to multiple external stimuli have shown great potential in many fields, including optic and sensing. Particularly, the photoswitchable ML property for these materials is fundamental to their applications but remains a formidable challenge. Herein, photoswitchable ML is successfully realized by endowing reversible photochromic properties to an ML molecule, namely 2-(1,2,2-triphenylvinyl) fluoropyridine (o-TPF).

Tannins amount determines whether tannase-containing bacteria are probiotic or pathogenic in IBD.

The role of dietary tannin in inflammatory bowel disease (IBD) is still not clear. Therefore, we aim to study the effect of TA in the progression of IBD. Dextran sulphate sodium (DSS)-induced model was used to mimic IBD.

Capsaicin regulates dyslipidemia by altering the composition of bile acids in germ-free mice.

The improvement of lipid metabolism by capsaicin (CAP) has been extensively studied, mostly with respect to the vanilloid type 1 (TRPV1) ion channel and intestinal flora. In this study, a model was established in germ-free mice by using resiniferatoxin (RTX) to ablate TRPV1 ion channels. Bile acid composition, blood parameters, and colonic transcriptome analyses revealed that CAP could improve dyslipidemia caused by high-fat diet even in the absence of TRPV1 ion channels and intestinal flora.

Construction of Photoresponsive 3D Structures Based on Triphenylethylene Photochromic Building Blocks.

Photoresponsive materials have been widely used in sensing, bioimaging, molecular switches, information storage, and encryption nowadays. Although a large amount of photoresponsive materials have been reported, the construction of these smart materials into precisely prescribed complex 3D geometries is rarely studied. Here we designed a novel photoresponsive material methyl methacrylate containing triphenylethylene (TrPEF-MA) that can be directly used for digital light processing (DLP) 3D printing.

NIR TADF emitters and OLEDs: challenges, progress, and perspectives.

Near-infrared (NIR) light-emitting materials show excellent potential applications in the fields of military technology, bioimaging, optical communication, organic light-emitting diodes (OLEDs), Recently, thermally activated delayed fluorescence (TADF) emitters have made historic developments in the field of OLEDs. These metal-free materials are more attractive because of efficient reverse intersystem crossing processes which result in promising high efficiencies in OLEDs. However, the development of NIR TADF emitters has progressed at a relatively slower pace which could be ascribed to the difficult promotion of external quantum efficiencies.

Recent Development of Photodeformable Crystals: From Materials to Mechanisms.

Photodeformable materials are a class of molecules that can convert photon energy into mechanical energy, which have attracted tremendous attention in the last few decades. Owing to their unique photoinduced deformable properties, including fast light-response and diverse mechanical behaviors, photodeformable materials have exhibited great potential in many practical applications such as actuators, photoswitches, artificial muscles, and bioimaging. In this review, we sort out the current state of photodeformable crystals and classify them into six categories by molecular structures: diarylethenes, azobenzenes, anthracenes, olefins, triarylethylenes, and other systems.

2-Hydroxybenzophenone Derivatives: ESIPT Fluorophores Based on Switchable Intramolecular Hydrogen Bonds and Excitation Energy-Dependent Emission.

In this work, a new series of 2-hydroxybenzophenone (BPOH) derivatives, BPOH-TPA, BPOH-PhCz, and BPOH-SF substituting with different electron-donating groups are designed and synthesized. Dual-emission spectra are observed in solutions indicating their excited-state intramolecular proton transfer (ESIPT) character. In solid states, all compounds exhibit a broad emission spectrum when excited at low excitation energy, deriving from the enol-type form stabilized by intramolecular hydrogen bonds.

Achieving 21% External Quantum Efficiency for Nondoped Solution-Processed Sky-Blue Thermally Activated Delayed Fluorescence OLEDs by Means of Multi-(Donor/Acceptor) Emitter with Through-Space/-Bond Charge Transfer.

Although numerous thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs) have been demonstrated, efficient blue or even sky-blue TADF-based nondoped solution-processed devices are still very rare. Herein, through-space charge transfer (TSCT) and through-bond charge transfer (TBCT) effects are skillfully incorporated, as well as the multi-(donor/acceptor) characteristic, into one molecule. The former allows this material to show small singlet-triplet energy splitting (Δ ) and a high transition dipole moment.

Blue TADF Emitters Based on Indenocarbazole Derivatives with High Photoluminescence and Electroluminescence Efficiencies.

A series of blue thermally activated delayed fluorescence (TADF) emitters were designed and synthesized using 2,4,6-triphenyl-1,3,5-triazine as the acceptor unit and indenocarbazole derivatives as the electron-donating moiety. In contrast with other six-membered heterocycles, like phenothiazine, phenoxazine, and dihydroacridine, where the TADF efficiency is affected by the presence of different conformers, indenocarbazole derivatives do not show this effect. Therefore, InCz23FlTz, InCz23DPhTz, InCz23DMeTz, and InCz34DPhTz allow the investigation of the effect of different substituents and substitution positions on TADF properties, without the influence of different conformations.

Dynamics of aggregated states resolved by gated fluorescence in films of room temperature phosphorescent emitters.

Phenazine derivative molecules were studied using steady state and time resolved fluorescence techniques and demonstrated to lead to strong formation of aggregated species, identified as dimers by time dependent density functional theory calculations. Blended films in a matrix of Zeonex®, produced at different concentrations, showed different contributions of dimer and monomer emissions in a prompt time frame, e.g.

Intramolecular Charge Transfer Controls Switching Between Room Temperature Phosphorescence and Thermally Activated Delayed Fluorescence.

Chemical modification of phenothiazine-benzophenone derivatives tunes the emission behavior from triplet states by selecting the geometry of the intramolecular charge transfer (ICT) state. A fundamental principle of planar ICT (PICT) and twisted ICT (TICT) is demonstrated to obtain selectively either room temperature phosphorescence (RTP) or thermally activated delayed fluorescence (TADF), respectively. Time-resolved spectroscopy and time-dependent density functional theory (TD-DFT) investigations on polymorphic single crystals demonstrate the roles of PICT and TICT states in the underlying photophysics.