Journal of The Chinese Chemical Society最新文献

The present work elucidates the first report on the synthesis and energy applications of the novel BaLa₂MnS₅ prepared from single source precursor route. This metal chalcogenide expressed a tuned band gap of 3.84 eV and an average crystallite size of 20.52 nm. Functional groups explored for BaLa₂MnS₅ expressed strong signals for presence of the metal sulfide bonds. The thermal decomposition pattern of BaLa₂MnS₅ followed a two-phased mechanism. Synthesized metal sulfide possessed an irregular morphology with particles arranged in random manner. An assessment of the chalcogenide BaLa₂MnS₅ for energy applications has been carried out. When employed as an electrode material in 1 M KOH, which acted as the background electrolyte, BaLa₂MnS₅ chalcogenide showed a specific capacitance of 597 F g⁻¹. Furthermore, this BaLa₂MnS₅ chalcogenide decorated electrode has a low resistance, as shown by the R_s of 1.35 Ω, and a specific power density of 7366 W kg⁻¹, according to the impedance investigations. The electrochemical results for the OER activity are indicative of the OER overpotential and Tafel slope values as 388 mV and 108 mV/dec. This electrode achieved the HER overpotential value of 241 mV while the obtained Tafel slope was 194 mV/dec.

Synchrotron protein crystallography (PX) remains an indispensable tool for uncovering the atomic structures of biomolecules. TLS 15A1, operated by the protein diffraction group of NSRRC, has been accessible to both academic and industrial users since January 2013. This beamline is energy-tunable within a range between 5.6 and 15.5 keV, which is suitable for phasing experiments. Over the past 11 years, TLS 15A1 has supported 657 projects and facilitated 1523 experiments across 41,656 h of beamtime. This article describes the beamline layout, studies of factors influencing data quality, and significant scientific contributions.

Inspired by the profound allure of the exquisitely regulated characteristics exhibited by 2-hydroxy-1-naphthaldehyde-triphenylamine (TPHY) and its derivatives in the realms of photochemistry and photophysics, our current endeavor primarily revolves around delving into the intricacies of photo-induced excited state reactions for TPHY fluorophores within solvents boasting varying degrees of polarity. Our simulations, resulting from variations in geometry and vertical excitation charge reorganization, unveil solvent polarity-dependent hydrogen bonding interactions and charge recombination induced by photoexcitation that can significantly enhance the excited state intramolecular proton transfer (ESIPT) reaction for TPHY chemosensor. By constructing potential energy surfaces (PESs), we reveal that the single ESIPT reaction of TPHY occurs concurrently with alternative dual intramolecular hydrogen bonds (O1-H2···N3 and O4-H5···N6). We sincerely hope that the regulation of solvent polarity on excited state behaviors may pave the way for the development of innovative luminescent materials.

A novel ratiometric fluorescent assay was proposed for protamine and heparin based on blue-emitting N,P-doped carbon dots (N,P-CDs) and green-emitting Eosin Y. The N,P-CDs were prepared using arginine as carbon and nitrogen sources according to hydrothermal method with favorable luminescence intensity, photostability, and good reproducibility. And the N,P-CDs were used as internal reference fluorescence molecules. The anionic Eosin Y was used as fluorescence signal molecule. Protamine with positive group could interact with Eosin Y through electrostatic effect, leading to the fluorescence quenching of Eosin Y. Upon the addition of heparin, heparin was combined with protamine with stronger affinity through electrostatic interactions and hydrogen bonds, which preventing the bonding of protamine with Eosin Y and obvious fluorescence emissions of Eosin Y at 538 nm could be observed. Meanwhile, the fluorescence signal of N,P-CDs at 420 nm remained stable during the whole process. A good linear range between the fluorescence emission intensity ratio of I₅₃₈/I₄₂₀ was obtained for protamine from 0.01 to 40 μg/mL with a low detection limit of 5.6 ng/mL, and heparin from 0 to 35 μg/mL with a low detection limit of 2.5 ng/mL. Moreover, the method was further applied to detection of heparin with satisfactory results in fetal bovine serum samples.

This study introduced a versatile class of indole-based benzimidazolium salts, offering distinct advantages: (1) the utilization of affordable and easily accessible starting materials; (2) a straightforward and uncomplicated synthesis process; (3) the diversity of the salt should provide fine-tunability of steric and electronic properties. These salts, employed as N-heterocyclic carbene (NHC) precursors, were effectively utilized in the Pd-catalyzed C–C bond formation reactions involving aryl or benzyl halide. The catalytic system, arising from the in situ generation of Pd(OAc)₂ and indole-based benzimidazolium salts, demonstrated remarkable efficiency. It accomplished the synthesis of diarylmethanes via the Suzuki coupling of benzyl chlorides and arylboronic acids in aqueous media with a Pd loading of 0.5 mol%. Furthermore, it successfully achieved the one-pot sequential Heck/Suzuki coupling reactions with a Pd loading of as low as 0.25 mol%.

Protein tyrosine phosphorylation plays a critical role in initiating upstream cellular signaling transduction. However, the challenge in biological samples is the variability in relative concentrations (0.1%) of site-specific tyrosine phosphorylation on proteins. To navigate these fluctuations and accurately quantify the absolute levels of tyrosine phosphosites among different samples, we reported a hybrid data-independent acquisition-parallel reaction monitoring (DIA-PRM) MS technique for the robust identification and quantification of the phosphoproteome, the establishment of a comprehensive library of tyrosine phosphosites, and the specific assessment of changes in tyrosine phosphorylation. In our model study on non-small cell lung cancer cells, our PRM strategy accomplished by a spiked-in synthetic heavy phosphopeptide demonstrated reliable targeted quantification of the pY1197 on EGFR, revealing levels of 2.5, 4.9, and 5.3 fmol in pervanadate (PV)-treated cells at 0, 15, and 30 min, respectively. Additionally, DIA-extensive phosphoproteomic analysis provided 2765 tyrosine phosphosites within 14,961 global phosphosites corresponding to 1536 phosphoproteins, contributing to the phospho-library establishment and relative quantification of phosphorylation level, especially in the PV-treated time-dependent increase of ErbB signaling pathway. This hybrid DIA-PRM approach will advance the application of precise measurement of changes in multiple phosphotyrosine residues and enhance our understanding of phosphoproteomic dynamics in drug-resistant cascades.

In this paper, the influence of different substitutions and different positions on proton transfer process of BOHMB derivatives has been systematically studied theoretically. Frontier molecular orbitals (MOs) demonstrate the intramolecular charge transfer and the charge redistribution promotes the occurrence of ESIPT. The substitution and position of NH2 and NO2 groups will regulate the excited-state energy barrier and thus affect the ESIPT process. More details about this figure will be discussed by Dr. Yaodong Song and his co-worker on page 576–587 in this issue.

We synthesized a pyrene-based sensitive fluorescent chemosensor, TPA-Cl ((E)-N,N,N-trimethyl-2-oxo-2-(2-(pyren-1-ylmethylene)hydrazinyl)ethan-1-aminium chloride), to detect hypochlorite in a perfect aqueous solution. TPA-Cl showed high selectivity for hypochlorite through fluorescence color change from sky blue to blue. The detection limit for hypochlorite was calculated as 0.27 μM, which is a quite low value. Moreover, the presence of other anions or ROS hardly hindered the sensing of hypochlorite by TPA-Cl. Furthermore, TPA-Cl could be applied successfully as a test kit for the simple recognition of hypochlorite. Surprisingly, TPA-Cl is the first pyrene-based fluorescent chemosensor that can detect ClO⁻ by using the TPA-Cl-coated test kit. Moreover, TPA-Cl could achieve the quantification of ClO⁻ in various environmental water samples. The hydrolytic cleavage and oxidation mechanism of TPA-Cl by hypochlorite was elucidated through UV–vis and fluorescent spectroscopy, ¹H NMR titration, ESI-MS analysis and DFT calculation.