Notes

To prevent tricks of a dielectric compound along polygonal closed-loop geometries inside a solitary water droplet.
The use of a squaramide-based ion pair receptor offers a solution to the very challenging problem of extraction and transport of extremely hydrated sulfate salt. Herein we demonstrate for the first time that a neutral receptor is able not only to selectively extract but also to transport sulfates in the form of an alkali metal salt across membranes and to do so in a cooperative manner while overcoming the Hofmeister bias. This was made possible by an enhancement in anion binding promoted by cation assistance and by diversifying the stoichiometry of receptor complexes with sulfates and other ions. The existence of a peculiar 41 complex of receptor 2 with sulfates in solution was confirmed by UV-vis and 1H NMR titration experiments, DOSY and DLS measurements, and supported by solid-state X-ray measurements. By varying the separation technique and experimental conditions, it was possible to switch the depletion of the aqueous layer into extremely hydrophilic or less lipophilic salts, thus obtaining the desired selectivity.Long-term thermal stability is one limiting factor that impedes the commercialization of the perovskite solar cell. Inspired by our prior results from machine learning, we discover that coating a thin layer of 4,4'-dibromotriphenylamine (DBTPA) on top of a CH3NH3PbI3 layer can improve the stability of resultant solar cells. The passivated devices kept 96% of the original power conversion efficiency for 1000 h at 85 °C in a N2 atmosphere without encapsulation. Near-ambient pressure X-ray photoelectron spectroscopy (XPS) was employed to investigate the evolution of the composition and evaluate thermal and moisture stability by in situ studies. A comparison between pristine MAPbI3 films and DBTPA-treated films shows that the DBTPA treatment suppresses the escape of iodide and methylamine up to 150 °C under 5 mbar humidity. Furthermore, we have used attenuated total reflection Fourier transform infrared and XPS to probe the interactions between DBTPA and MAPbI3 surfaces. The results prove that DBTPA coordinates with the perovskite by Lewis acid-base and cation-π interaction. Selleckchem PT-100 Compared with the 19.9% efficiency of the pristine sample, the champion efficiency of the passivated sample reaches 20.6%. Our results reveal DBTPA as a new post-treating molecule that leads not only to the improvement of the photovoltaic efficiency but also thermal and moisture stability.A smooth traceless ligation strategy using an air-stable phosphane probe (2-(diphenylphosphanyl)phenyl)methanol as a C-terminus activator has been demonstrated at simple and sterically hindered amino acid junctions (Gly, Ala, Trp, Glu). This Staudinger peptide ligation proceeds via formation of a seven-membered transition state to afford di-, tetra-, and pentapeptides in 78-95% yields. The experimental results of ligation at Gly junction and regioselective ligation at Glu junction were theoretically studied by computational calculations. These findings established the versatile behavior of our synthesized phosphane probe for Staudinger peptide ligation toward synthesizing peptides and proteins of choice.To develop an effective method for probing O- and N-glycosyltransfer reactions that are accompanied by the release of undecaprenyl pyrophosphate, solanesyl pyrophosphate (SPP) is used as a surrogate to bind a terpyridine zinc complex (Tpy-Zn), forming a fluorescent [Tpy-Zn]-SPP complex (Kass 106,000 M-1 in EtOH-CHCl3) with 5.8 μM LOD in HEPES buffer (10 mM, pH 7.4) containing 10 mM CaCl2 and 0.08% decyl PEG, which is similar to the bioassay conditions for lipid II polymerization.In view of the importance of both fluorinated synthons and homoenolate equivalents, synthetic application of difluorocyclopropanols is desired but remains challenging due to their thermodynamic instability. Herein, we use siloxydifluorocyclopropanes as difluorocyclopropanol precursors to carry out new Cu-catalyzed ring-opening defluorinative alkylation. With α-bromo carboxylic esters as coupling partners, the reaction affords γ-fluoro-δ-ketoesters via a CuI/CuII catalytic cycle. Interestingly, by the use of α-bromoamides, the ring-opening defluorinative alkylation is followed by an additional intramolecular C-N oxidative coupling to deliver a lactam intermediate, which further undergoes defluorination, hydrolysis, ring opening, and dehydration cascade via a CuI/CuII/CuIII catalytic pathway, leading to γ,δ-diketonitriles as the final products.A series of 5,7,9-substituted 2-azapyrenes were synthesized for the first time. The synthesis relies on Brønsted acid promoted benzannulation of alkyne precursors prepared by palladium-catalyzed cross-coupling reactions. The synthetic strategy is efficient and the scope covers a variety of functional groups. The electrochemical behavior and photophysical properties of the products were investigated by UV-vis and fluorescence spectroscopy, cyclic voltammetry, and DFT calculations.Bismuth halide perovskites have recently been considered a potential alternative to lead halide analogues due to their low toxicity and high stability. However, the layered flake structure and wide band gap limit their applications in perovskite solar cells (PSCs). We herein show that large-grained all-inorganic bismuth-based perovskites with a narrow band gap can be obtained from a Lewis acid-base adduct reaction under ambient conditions. Thiourea (CH4N2S) is utilized as a Lewis base to interact with BiI3, confirmed with infrared (IR) spectra. The strong coordination between thiourea and the Bi3+ center could slow down the perovskite crystallization and promote the preferred orientation of the perovskite crystals with a hexagonal phase. The morphology of the perovskite films varies dramatically with an increase of molar ratio of BiI3 and thiourea in the precursor. The perovskites derived from a BiI3/thiourea ratio of 12 display extrathick grains, higher surface coverage, extended light absorption, higher crystallinity, and similar air stability compared to the pristine sample. The power conversion efficiency (PCE) of the thiourea-induced bismuth perovskite solar cells is significantly enhanced due to the higher surface coverage and the broader absorption of the perovskite film.
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