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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.

The research in circularly polarized luminescence has attracted wide interest in recent years. Efforts on one side are directed toward the development of chiral materials with both high luminescence efficiency and dissymmetry factors, and on the other side, are focused on the exploitations of these materials in optoelectronic applications. This review summarizes the recent frontiers (mostly within five years) in the research in circularly polarized luminescence, including the development of chiral emissive materials based on organic small molecules, compounds with aggregation-induced emissions, supramolecular assemblies, liquid crystals and liquids, polymers, metal-ligand coordination complexes and assemblies, metal clusters, inorganic nanomaterials, and photon upconversion systems. In addition, recent applications of related materials in organic light-emitting devices, circularly polarized light detectors, and organic lasers and displays are also discussed.

Materials with circularly polarized luminescence properties have attracted wide attention in recent years. One of the most important applications of these materials is for circularly polarized organic light emitting diodes (CP-OLEDs), which have potential application in 3D displays. Chiral conjugated polymers, small organic molecules and metal complexes have already been employed as emitters for CP-OLEDs. Benefiting from the ability to harvest both singlet and triplet excitons, chiral phosphorescent metal complexes always show outstanding device performance. In this article we briefly discuss the recent progress, current challenges and out look of chiral phosphorescent metal complexes.

Circularly polarized organic light-emitting diodes (CP-OLEDs) have received considerable attention due to their promising applications in 3D displays. However, up to now, CP-OLEDs using iridium(III) phosphors as emissive dopants exhibited low brightness, insufficient efficiency, serious efficiency roll-off, and especially low electroluminescence dissymmetry factors (gEL). In this study, a blue Ir(III) complex Ir(dfppy)2(sdpp) (dfppy is 2-(2,4-difluorophenyl)pyridine, sdpp is pyridinylphosphorothioate) peaking at 466 nm was synthesized, and two pairs of enantiomers containing the λ or δ isomer together with a chiral phosphine center (R or S) were separated into λ-Ir(dfppy)2(S-sdpp), δ-Ir(dfppy)2(R-sdpp), λ-Ir(dfppy)2(R-sdpp) and δ-Ir(dfppy)2(S-sdpp), respectively. It is the first example to investigate phosphine chirality in an Ir(III) complex, and the electron cloud distribution in the chiral conjugated ancillary ligand and λ/δ chirality of the Ir(III) center induced Ir(dfppy)2(sdpp) to exhibit decent circularly polarized luminescence (CPL) activities with a dissymmetry factor (|gPL|) around 1.4 × 10−3. The OLEDs based on Ir(dfppy)2(sdpp) exhibited a maximum external quantum efficiency of 13.8% with mild efficiency roll-off. Notably, the CP-OLEDs based on λ-Ir(dfppy)2(S-sdpp), δ-Ir(dfppy)2(R-sdpp), λ-Ir(dfppy)2(R-sdpp) and δ-Ir(dfppy)2(S-sdpp) showed obvious circularly polarized electroluminescence (CPEL) signals with a gEL of −2.1 × 10−3, 2.4 × 10−3, −2.1 × 10−3 and 1.9 × 10−3, respectively, thus affording an efficient strategy for the design of chiral blue Ir(III) emitters and their CP-OLEDs.

In this work, two cyclometalated ligands 2-(pyridin-2-yl)indolo[3,2,1-jk]carbazole (pyidcz) and 2-(4-(trifluoromethyl)pyridin-2-yl)indolo[3,2,1-jk]carbazole (tfpyidcz) containing an indolo[3,2,1-jk]carbazole unit were synthesized for achieving highly efficient iridium(III) complexes (pyidcz)2Ir(tmd) and (tfpyidcz)2Ir(tmd) (tmd = 2,2,6,6-tetramethyl-3,5-heptanedione). The two Ir(III) complexes exhibit emissions peaking at 499 and 554 nm, respectively, with narrow full width at half maximum (FWHM) values of 35 and 53 nm, respectively, short phosphorescence lifetimes less than 1 μs and high photoluminescence quantum yields of up to 90% in CH2Cl2 solution. The organic light-emitting diodes (OLEDs) with (pyidcz)2Ir(tmd) and (tfpyidcz)2Ir(tmd) emitters show good performances. The (pyidcz)2Ir(tmd)-based device shows a turn-on voltage (Von) of 3.6 V with a maximum brightness (Lmax) of 39123 cd m−2, a maximum current efficiency (ηc,max) of 69.2 cd A−1, a maximum power efficiency (ηp,max) of 36.8 lm W−1 and a maximum external quantum efficiency (EQEmax) of 21.2%. In particular, the FWHM bandwidth of the electroluminescence spectrum is only 33 nm, which was rarely reported for Ir(III) complex-based OLEDs. The performance of the (tfpyidcz)2Ir(tmd)-based device is slightly better with a Von of 3.3 V, a Lmax of 31714 cd m−2, a ηc,max of 78.4 cd A−1, a ηp,max of 54.7 lm W−1 and an EQEmax of 24.0%. Furthermore, the efficiency roll-offs of both devices are small, and the ηc values at 10 000 cd m−2 brightness are still maintained at 60.0 and 71.4 cd A−1, respectively, which provide a powerful reference for developing indolo[3,2,1-jk]carbazole-based Ir(III) complexes for efficient OLEDs.

In this study, we report the first circularly polarized white organic light-emitting diodes (CP-WOLEDs) based on all thermally activated delayed fluorescence (TADF) materials. Two pairs of spiro-type TADF enantiomers, (R/S)-SPOCN (5,5'-((2,2',3,3'-tetrahydro-1,1'-spirobi[indene]-7,7'-diyl)bis(oxy))bis(4-(10H-phenoxazin-10-yl)phthalonitrile)) and (R/S)-OSFSO (2'-(trifluoromethyl)-spiro[quinolino[3,2,1-kl]phenoxazine-9,9'-thioxanthene]-10',10'-dioxide), serve as emitters with complementary emission. The CP-OLEDs exhibit warm white emission with a CIE coordinate of (0.35, 0.46). Besides, decent device performances are observed with an external quantum efficiency of up to 21.6 % at maximum and 11.8 % at 1000 cd m

In this paper, utilizing the same recognition group dinitrophenyl and hydroxyl functional NIR fluorophore hemicyanine, directly-linked probe CyNO2 and self-immolative probe CyBNO2 were developed for evaluation of sensing PhSH. Though CyNO2 was easily synthesized and sensitive to mercapto, the probe CyBNO2 showed higher selectivity, broader linear range from 1.0 × 10−7 to 7.0 × 10−6 M with lower detection limit of 22 nM for PhSH. Moreover, CyBNO2 was successfully applied for monitoring PhSH in living cells and in vivo, indicating the great potential of self-immolative probes.

Selenocysteine (Sec, pKa 5.8) is genetically encoded 21st amino acid into the active site of selenoproteins, which have broad functions relevant to various diseases, tissues or organs and subcellular organelles. However, many selenoproteins involved cellular functions still remains unclear. In addition, since biothiols such as glutathione (GSH, pKa 8.3), possessing similar chemical properties with Sec, commonly exist in living systems at high levels. Thus, it is of great importance and high challenge to identify novel probes for selectively monitoring Sec over biothiols. In this paper, we proposed a smart strategy which allowed us to develop a lysosome targetable probe for specifically sensing Sec. By restricting weak acidic microenvironment, the probe shows a specific detection for Sec with 85-fold fluorescence enhancement owing to the remaining high activity of Sec at pH 5.0. Moreover, being low cytotoxicity to the cells verified by MTS assay, the probe was then successfully applied for imaging exogenous and endogenous Sec in lysosomes, indicating its potential for the biological investigation of Sec in subcellular organelles.

An acylamino and hydroxyl functionalized hydrogel [p(HMAm/HEA)] was newly prepared by the

Surface water

Dairy industry has become an increasingly important enterprise in China as people's dietary preferences and composition have changed dramatically with rapid economic development in the past several decades. A number of problems, however, exist in China's relatively young dairy industry, including the imbalanced allocation of profits throughout the dairy supply chain. One of the root causes of the melamine infant powered milk scandal in 2008 was the unfair profit allocation mechanism in dairy supply chain. The revenue sharing contract approach has proven to be effective in generating market shares and total profits. In this study, we apply the three-stage revenue sharing contract model of Giannoccaro and Pontrandolfo (2004) in an analysis of dairy supply chain to explore its problems in profit allocation and possible solutions to them. The analysis was conducted by a case study of Hohhot, often called as “milk capital of China”. Our results show that the current profit distribution in the dairy supply chain is not balanced: the supermarket's profit>farmer's profit>manufacturer's profit. Under the revenue sharing contract setting, the dairy industry's total profit increased by 12.49%. By exploring different parameters in the revenue sharing contract model, we have found that a win-win situation can be created among all the members of the supply chain. In dairy supply chain, the ratio of the revenue reserved for the supermarket itself is equal or greater than 47% and the ratio of the revenue reserved for the manufacturer itself is between 46.4 and 50.2%. The values of the parameters that generate a sustainable or win-win situation are related to the bargaining position in the dairy supply chain. The revenue sharing contract has proven to be effective and desirable by all the dairy chain partners in dairy supply chain. The results of this study provide relevant information for improving the dairy supply chain structure and the revenue sharing contract model can be applied to other industries, sectors and regions.