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In its crystalline state, a dinuclear Cu-based metallocycle discriminates between the three isomers of xylene with liquid-phase selectivity in the order -xylene ≫ -xylene ≫ -xylene. This selectivity holds over a wide concentration range, with -xylene concentrations as low as 5%. Single-crystal X-ray diffraction and gas chromatography further indicate that the metallocyclic host extracts trace amounts of -xylene from commercially pure -xylene (≥99%); using NMR spectroscopy, we show that the metallocycle exhibits exclusive selectivity for -xylene. Crystallographic studies show that the selectivity is based on the size and shape of the guest in combination with the flexibility of the host.
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http://dx.doi.org/10.1021/jacs.9b11314 | DOI Listing |
J Chromatogr A
September 2025
Environment Research Institute, Shandong University, Qingdao, 266237, China. Electronic address:
On-site accurate and real-time monitoring of trace chemical warfare agents is a critical component of national security surveillance. In this study, a photoionization-induced chemical ionization time-of-flight mass spectrometry is developed for the detection of trace gaseous chemical warfare agents under ambient conditions. Firstly, a benzene-toluene-xylene mixture standard gas is utilized to optimize the instrument parameters, followed by screening of dopants for chemical warfare agents detection, with methanol ultimately identified as the optimal dopant.
View Article and Find Full Text PDFJ Chromatogr A
September 2025
Luoyang R&D Center of Technology, SINOPEC Engineering (Group) Co., Ltd, Luoyang 471003, China. Electronic address:
Conventional one-dimensional gas chromatography methods for gasoline quality monitoring require separate analyses for different component classes, limiting analytical efficiency and unconventional additive detection. This study presents a comprehensive two-dimensional gas chromatography with flame ionization detection (GC × GC-FID) platform enabling simultaneous quantification of regulated components and rapid screening of unconventional additives in a single analytical run. The method achieved excellent agreement with ASTM standards and high repeatability for BTEX (benzene, toluene, ethylbenzene, and xylenes) and oxygenates in gasoline.
View Article and Find Full Text PDFEcotoxicol Environ Saf
September 2025
Xiangya School of Public Health, Central South University, Changsha 410078, China. Electronic address:
Background: The link between exposure to environmental hazards and thyroid function has been relatively well established. However, evidence on environmental exposure to volatile organic compounds (VOCs) and thyroid function in the general population remains unclear.
Objectives: To assess the impact of individual and joint effects of VOCs exposure on thyroid function in a representative sample of U.
Angew Chem Int Ed Engl
September 2025
Guangdong Provincial Key Laboratory of New Energy Materials Service Safety, Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, China.
Halogenation emerges as a key strategy to enhance the performance of organic solar cells (OSCs) by tuning molecular packing, energy levels, and charge dynamics. Here, we report three new benzo[a]phenazine-core small-molecule acceptors, namely NA5, NA6, and NA7, and systematically evaluate their photovoltaic properties in o-xylene-processed binary and ternary OSCs. Halogenation significantly strengthens intermolecular interactions, improves charge carrier mobility, and facilitates exciton dissociation, leading to a remarkable increase in binary device efficiencies from ∼2% (NA5) to over 17% (NA6, NA7).
View Article and Find Full Text PDFPolymers (Basel)
August 2025
The Institute of Nuclear Physics, Ibragimov Str. 1, Almaty 050032, Kazakhstan.
To develop membranes capable of efficient and switchable emulsion separation under variable pH conditions, pH-responsive surfaces were engineered on poly(ethylene terephthalate) track-etched membranes (PET TeMs) via a two-step UV-initiated RAFT graft polymerization process. Initially, polystyrene (PS) was grafted to render the surface hydrophobic, followed by the grafting of poly(methacrylic acid) (PMAA) to introduce pH-responsive carboxyl groups. Optimized conditions (117 mM MAA, RAFT:initiator 1:10, 60 min UV exposure at 10 cm) resulted in PET TeMs-g-PS-g-PMAA surfaces exhibiting tunable wettability, with contact angles shifting from 90° at pH 2 to 65° at pH 9.
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