Star-Shaped and Fused Electron Acceptors based on C3h -Symmetric Coplanar Trindeno[1, 2-b: 4, 5-b': 7, 8-b'']trithiophene Core for Non-Fullerene Solar Cells.

Two new star-shaped and fused electron acceptors, TITT-3IC and TITT-3ICF have been designed and synthesized, which consist of a C3h -symmetric coplanar trindeno[1, 2-b: 4, 5-b': 7, 8-b'']trithiophene (TITT) as the central core and 3-(dicyanomethylidene)indan-1-one and 2-(5,6-difluoro-3-oxo-2,3-dihydro-1H-inden-1-ylidene) malononitrile as the peripheral electron-withdrawing groups, respectively. With the large coplanar configuration and electron-rich nature of π-conjugated backbone, these two acceptors exhibit strong intermolecular charge transfer absorption in the region of 500-650 nm with the optical band gaps around 1.9 eV. Relative to TITT-3IC, TITT-3ICF shows the downshifted LUMO level and the slightly redshifted absorption with the higher molar extinction coefficient due to the stronger electron-withdrawing effect of fluorination. When blending with PTB7-Th, the TITT-3ICF-based device displays a higher power conversion efficiency (PCE) of 4.26 % than the TITT-3IC-based device (PCE=3.87 %). Comparing with the TITT-3IC-based device, the increased short circuit current (JSC ) and fill factor (FF) are responsible for the higher PCE value of the TITT-3ICF-based device, which benefits from its strong and redshifted absorption for light harvesting and proper phase separation morphology for effective exciton dissociation and charge transport. This work demonstrates that as an alternative electron-donating core, TITT will be promising in designing star-shaped non-fullerene materials.

Synthesis of α,ß-Unsaturated Amidines through Gold-Catalyzed Intermolecular Reaction of Azides with Ynamides.

A concise and flexible synthesis of α,ß-unsaturated amidines via gold-catalyzed intermolecular ynamide amination/carbene 1,2-shift between ynamides and benzylic azides has been developed. Under mild reaction conditions, various α,ß-unsaturated amidines were obtained in mostly good yields, thus providing an efficient and atom-economic way for the construction of valuable α,ß-unsaturated amidines.

Solution-Processable Hyperbranched Conjugated Polymer Nanoparticles Based on C3h -Symmetric Benzotrithiophene for Polymer Solar Cells.

The development of photovoltaic polymers based on C3h -symmetric benzotrithiophene (C3h -BTT), an analogue of the well-known benzodithiophene (BDT) donor unit, has been severely limited due to difficult processability. Here the authors report the preparation of solution-processable C3h -BTT-based hyperbranched conjugated polymer nanoparticles (BTT-HCPNs) with tunable particle sizes via Stille miniemulsion polymerization. Compared with the corresponding star-shaped small molecule (C3h -BTT core with three diketopyrrolopyrrole arms, BTT-3DPP) with a wide bandgap (1.83 eV), both BTT-HCPNs show strong aggregation even in dilute solutions, leading to much-extended absorption (up to ≈1000 nm) and lower bandgaps (1.38 eV). The larger BTT-HCPN particle exhibits stronger aggregation and more extended absorption than the smaller one. As a result, solar cells fabricated from BTT-HCPNs/PC71 BM solutions show a power conversion efficiency up to 1.51% after DIO additive treatment, much higher than that of BTT-3DPP (0.31%).

Elevated plasma pyruvate kinase M2 concentrations are associated with the clinical severity and prognosis of coronary artery disease.

Introduction: Pyruvate kinase M2 (PKM2) was involved in the pathophysiology of atherosclerosis and coronary artery disease (CAD). We tested whether plasma PKM2 concentrations were correlated with clinical severity and major adverse cardiovascular events (MACEs) in CAD patients. Materials and methods: A total of 2443 CAD patients and 238 controls were enrolled. The follow-up time was two years. Plasma PKM2 concentrations were detected by enzyme-linked immunosorbent assay (ELISA) kits (Cloud-Clone, Wuhan, China) using SpectraMax i3x Multi-Mode Microplate Reader (Molecular Devices, San Jose, USA). The predictors of acute coronary syndrome (ACS) were assessed by logistic regression analysis. The association between PKM2 concentration in different quartiles and MACEs was evaluated by Kaplan-Meier (KM) curves with log-rank test and Cox proportional hazard models. The predictive value of PKM2 and a cluster of conventional risk factors was determined by Receiver operating characteristic (ROC) curves. The net reclassification improvement (NRI) and the integrated discrimination improvement (IDI) were utilized to evaluate the enhancement in risk prediction when PKM2 was added to a predictive model containing a cluster of conventional risk factors. Results: In CAD patients, PKM2 concentration was the independent predictor of ACS (P < 0.001). Kaplan-Meier cumulative survival curves and Cox proportional hazards analyses revealed that patients with a higher PKM2 concentration had higher incidence of MACEs compared to those with a lower PKM2 concentration (P < 0.001). The addition of PKM2 to a cluster of conventional risk factors significantly increased its prognostic value of MACEs. Conclusion: Baseline plasma PKM2 concentrations predict the clinical severity and prognosis of CAD.

Synthesis of 2H-Chromenes via Unexpected [4 + 2] Annulation of Alkynyl Thioethers with o-Hydroxybenzyl Alcohols.

A novel Brønsted acid-catalyzed reaction of alkynyl thioethers with o-hydroxybenzyl alcohols via an unexpected formal [4 + 2] annulation has been developed. This metal-free protocol leads to the facile and practical synthesis of valuable polysubstituted 2H-chromenes in mostly good to excellent yields under mild reaction conditions and features a wide substrate scope and excellent functional group tolerance.

Characteristics of nitrogen and phosphorus adsorption by Mg-loaded biochar from different feedstocks.

Herein, biochars from 6 different feedstocks (taro straw, corn straw, cassava straw, Chinese fir straw, banana straw, and Camellia oleifera shell) were produced using magnesium chloride (MgCl2) as a modifier due to their sorption behavior toward NH4+-N and phosphorus in an aqueous solution. The biochar characteristics were evaluated, including pH, pHPZC, biochar magnesium content, and total pore volume (PVtot). The experimental results in terms of the kinetics and equilibrium isotherms showed that the cassava straw and banana straw biochars exhibited the theoretical maximum saturated adsorption capacities of 24.04 mg·g-1 (NH4+-N) and 31.15 mg·g-1 (TP), respectively. Biochar produced from these feedstocks had higher magnesium contents and greater total pore volumes, reflecting the significant contributions from magnesium and steric effects. FTIR, XRD, and SEM/EDS analyses demonstrated that NH4+-N and TP sorption mechanisms predominantly involved surface electrostatic attraction, Mg2+ precipitates and complexation with surface hydroxyl functional groups.

Star-Shaped Fused-Ring Electron Acceptors with a C3h-Symmetric and Electron-Rich Benzotri(cyclopentadithiophene) Core for Efficient Nonfullerene Organic Solar Cells.

Classical fused-ring electron acceptors (FREAs) with a linear acceptor-donor-acceptor (A-D-A) architecture continuously break records of power conversion efficiency (PCE) in nonfullerene organic solar cells. In contrast, the development of star-shaped FREAs still lags behind. Herein, a new C3h-symmetric and electron-rich core, benzotri(cyclopentadithiophene) (BTCDT) in which the central benzo[1,2-b:3,4-b':5,6-b″]trithiophene fused with three outer thiophenes via three cyclopentadienyl rings, is synthesized and used for the construction of star-shaped FREAs (BTCDT-IC and BTCDT-ICF). Owing to the strong electron-donating ability of the BTCDT unit, both acceptors exhibit the effective intramolecular charge transfer, leading to the strong absorption in the region of 500-800 nm with narrow band gaps below 1.70 eV as well as suitable highest occupied molecular orbital and lowest unoccupied molecular orbital levels. Compared with nonfluorinated BTCDT-IC, fluorinated BTCDT-ICF red-shifts the absorption peak to 688 nm and reduces the band gap to 1.62 eV, which induces a broader external quantum efficiency (EQE) response ranging from 300 to 800 nm and a higher maximum EQE of 70% while blending with a wide band gap polymer donor J61. The J61:the BTCDT-ICF blend film exhibits more suitable phase morphology compared with the J61:BTCDT-IC blend film, which is responsible for the enhanced EQE value, increased short-circuit current density (JSC), and fill factor (FF) in organic solar cell devices. As a result, the J61:BTCDT-ICF-based device yields a best PCE of 8.11% with a high JSC of 16.93 mA cm-2 and a high FF of 65.6%, demonstrating that the BTCDT-based star-shaped FREAs hold great potential for nonfullerene organic solar cells.