Chinese Journal of Chemistry最新文献

Layer-by-layer (LbL) solution processing is an efficient method to realize high performance organic solar cells (OSCs). One of the drawbacks of the LbL-processed active layer is the large difference in the crystallinity of the donor and acceptor, which will lead to imbalance charge transfer and result in unfavorable charge recombination. Herein, we combined a novel volatile additive 3,5-dichloro-2,4,6- trifluorobenzotrifluoride (DTBF) with the LbL method to realize high-efficiency OSCs. DTBF interacts with the non-fullerene acceptor BTP-4F by non-covalent bonding, which enhances the crystallinity and compact stacking of BTP-4F. DTBF doped OSC has balanced and efficient electron transport properties, longer carrier lifetime, higher exciton dissociation and charge collection efficiencies, lower energetic disorder than the control OSC without any additives. Benefiting from the optimization of charge dynamics and micro-morphology by DTBF, the binary LbL-processed OSC achieved synergistic improvements in open-circuit voltage, short-circuit current density and fill factor. As a result, a champion power conversion efficiency (PCE) of 19% is realized for DTBF-optimized OSC, which is superior to the control OSC (17.55%). This work demonstrates a promising approach to modulate active layer morphology and fabricate high performance OSCs.

Near-infrared (NIR)-absorbing polymerized small molecule acceptors (PSMAs) based on a Y-series backbone (such as PY-IT) have been widely developed to fabricate efficient all-polymer solar cells (all-PSCs). However, medium-bandgap PSMAs are often overlooked, while they as the third component can be expected to boost power conversion efficiencies (PCEs) of all-PSCs, mainly due to their up-shifted lowest unoccupied molecular orbital (LUMO) energy level, complimentary absorption, and diverse intermolecular interaction compared to the NIR-absorbing host acceptor. Herein, an IDIC-series medium-bandgap PSMA (P-ITTC) is developed and introduced as the third component into D18/PY-IT host, which can not only form complementary absorption and cascade energy level, but also finely optimize active layer morphology. Therefore, compared to the D18/PY-IT based parental all-PSCs, the ternary all-PSCs based on D18/PY-IT:P-ITTC obtain an increased exciton dissociation, charge transport, carrier lifetime, as well as suppressed charge recombination and energy loss. As a result, the ternary all-PSCs achieve a high PCE of 17.64% with a photovoltage of 0.96 V, both of which are among the top values in layer-by-layer typed all-PSCs. This work provides a method for the design and selection of the medium-bandgap third component to fabricate efficient all-PSCs.

Twelve new limonoids (1—12), named trichilitins A—L, were isolated from the leaves and twigs of Trichilia connaroides, together with ten known compounds (13—22). The structures were elucidated by extensive spectroscopic investigations, X-ray diffraction analyses, and ECD calculations. Compound 1, which belongs to a unique class of ring B-seco limonoid, has been identified as 6/7/6/5 tetracyclic due to a key Baeyer-Villiger oxidation. Compounds 2—7 were identified as ring intact limonoids, while compounds 8—10 were established as ring D-seco ones, and 11 and 12 were determined to be rearranged ones. All of the compounds were tested for cytotoxicity against three human tumor cell lines (HCT-116, NCl-H1975, and SH-SY5Y). Compounds 6, 7, 13, 14, and 19 exhibited significant cytotoxic effects, especially 7 exhibited significant cytotoxic effects against HCT-116 with an IC₅₀ value of 0.035 μmol·L^–1 and was more active than the positive control, doxorubicin with an IC₅₀ value of 0.20 μmol·L^–1. Compound 7 effectively induced apoptosis of HCT-116, which was associated with S-phase cell cycle arrest. Furthermore, the Western blot analysis showed that compound 7 could induce cell cycle arrest by promoting the expression levels of p53 and p21.