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Dynamic nuclear polarization (DNP) utilizing narrow-line electron spin clusters (ESCs) to achieve nuclear spin resonance matching (ESC-DNP) by microwave irradiation is a promising way to achieve NMR signal enhancements with a wide design scope requiring low microwave power at high magnetic field. Here we present the design for a trityl-based tetra-radical (TetraTrityl) to achieve DNP for H NMR at 7 T, supported by experimental data and quantum mechanical simulations. A slow-relaxing ( ≈ 1 ms) 4-ESC is found to require at least two electron spin pairs at <8 Å e-e spin distance to yield H ESC-DNP enhancement, while squeezing the rest of the e-e spin distances to <12 Å results in optimal H ESC-DNP enhancements. Fast-relaxing ESCs ( ≈ 10 μs) are found to require a weakly coupled narrow-line radical (sensitizer) to extract polarization from the ESC. These results provide design principles for achieving a power-efficient DNP at high field via ESC-DNP.
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http://dx.doi.org/10.1021/acs.jpclett.4c00182 | DOI Listing |
Dalton Trans
September 2025
Department of Chemical Sciences, Tezpur University, Napaam 784028, Sonitpur, Assam, India.
Reaction of [Mn(salophen)Cl] {salophen = -phenylenediamine bis(salicylidenaminato)} with a tricyano Fe(III) precursor complex, [Fe(bbp)(CN)] {Hbbp = bis(2-benzimidazolyl)pyridine}, affords a dinuclear cyano-bridged heterometallic Mn-(μ-NC)-Fe fragment in the complex salt [Mn(salophen)(HO)][Mn(salophen)(HO)(μ-NC)Fe(bbp)(CN)]·4HO (1). The title compound shows field-induced slow relaxation of magnetization below 2.8 K.
View Article and Find Full Text PDFPestic Biochem Physiol
November 2025
Anhui Provincial Key Laboratory of Hazardous Factors and Risk Control of Agri-food Quality Safety, School of Resource & Environment, Anhui Agricultural University, Hefei, Anhui 230036, China; Institute of Ecological Environmental Protection and Pollution Remediation Engineering, Anhui Agricultural U
Neonicotinoid insecticides residuals pose a threat to aquatic ecosystems and human health. Imidaclothiz, as a novel neonicotinoid pesticide, the metabolic mechanisms in aquatic environments was unclear. This study investigated the degradation characteristics of imidaclothiz in both pure and actual water, and analyzed the photodegradation and hydrolysis metabolites of imidaclothiz in aquatic environments and assessed their toxicity.
View Article and Find Full Text PDFAnal Chim Acta
November 2025
State Key Laboratory of Veterinary Public Health and Safety, Key Laboratory for Detection of Veterinary Drug Residues and Illegal Additives of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China. Electronic address: haiyang
Background: Aflatoxin B1 (AFB1) stands among the most toxic naturally occurring substances, with its acute toxicity characterized by the induction of acute hepatic necrosis, hemorrhage, and even fatal outcomes, thereby posing a profound threat to human health. Contamination of AFB1 in food commodities can arise at multiple stages throughout the production cycle, including cultivation, storage, and processing. This contamination cascade permeates the entire food supply chain, encompassing primary agricultural products as well as a diverse range of processed food items.
View Article and Find Full Text PDFACS Nano
September 2025
Materials Genome Institute, Shanghai University, Shanghai 200444, China.
RuO, the benchmark catalyst for the oxygen evolution reaction (OER), has traditionally been considered Pauli paramagnetic; however, recent findings have demonstrated its antiferromagnetic (AFM) properties, hinting at the opportunity to enhance RuO's OER performance by manipulating its magnetic traits. In this study, we successfully induced weak ferromagnetism in commercial RuO, transitioning it from an AFM state using an electrochemical sodiation method. This process resulted in high activity, achieving an overpotential of 145 mV to reach 10 mA cm and extending the service hours by more than 13 times compared to pristine RuO in 0.
View Article and Find Full Text PDFAdv Mater
September 2025
School of Chemistry and Biochemistry, School of Materials Science and Engineering, Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Molecular spin systems that can be chemically tuned, coherently controlled, and readily integrated within devices remain central to the realization of emerging quantum technologies. Organic high-spin materials are prime candidates owing to their similarity in electronic structure to leading solid-state defect-based systems, light element composition, and the potential for entanglement and qubit operations mediated through spin-spin exchange. However, the inherent instability of these species precludes their rational design, development, and application.
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