The interaction of iron with water-soluble polymer chitosan and monomer d-glucosamine is investigated by Mössbauer spectroscopy. The 4.2 K Mössbauer spectrum of Fe-water-soluble chitosan complex indicates the presence of a magnetic pattern and a quadrupole doublet, and analysis of the spectral data leads to the conclusion that an Fe(II) state is partially stabilized in this system. Fe-glucosamine (monomer of chitosan) complex, on the other hand, clearly stabilizes the Fe(II) state in the acidic pH range as evidenced from the isomer shift extracted from the Mössbauer spectra. The oxidation state of the metal ion in the complex is found to be pH dependent. Indirect evidence supporting the involvement of amino group in the bonding with the metal ion is discussed. From the analysis of the experimental data under varying experimental conditions, it is concluded that the metal ion in the complex is at least tetracoordinated and at most hexacoordinated with O/N ligands of the polymer or monomer and thus corroborates the bonding scheme proposed earlier.
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http://dx.doi.org/10.1021/bm020131n | DOI Listing |
Chem Sci
January 2025
State Key Laboratory of Powder Metallurgy, Central South University Changsha 410083 P. R. China
In overcoming the barrier of rapid Li transfer in lithium-ion batteries at extreme temperatures, the desolvation process and interfacial charge transport play critical roles. However, tuning the solvation structure and designing a kinetically stable electrode-electrolyte interface to achieve high-rate charging and discharging remain a challenge. Here, a lithium nonafluoro-1-butanesulfonate (NFSALi) additive is introduced to optimize stability and the robust solid electrolyte interface film (SEI), realizing a rapid Li transfer process and the structural integrity of electrode materials.
View Article and Find Full Text PDFFront Pharmacol
January 2025
Department of Oncology, Shengjing Hospital of China Medical University, Shenyang, China.
Breast cancer is the most commonly diagnosed cancer worldwide. Metal metabolism is pivotal for regulating cell fate and drug sensitivity in breast cancer. Iron and copper are essential metal ions critical for maintaining cellular function.
View Article and Find Full Text PDFThis work aimed at addressing the problem of hexavalent chromium pollution in the water environment, designing and preparing the Cu/CuO/NH-MIL-88B (Fe) heterojunction material with NH-MIL-88B (Fe) as the carrier, Cu/CuO was loaded on NH-MIL-88B (Fe) by light-assisted reduction. The loading of CuO effectively improves the visible light absorption capacity of the composite material. The SPR effect of Cu improves the separation and transfer of photogenerated carriers in the composite material.
View Article and Find Full Text PDFACS Cent Sci
January 2025
Institute of Organic Chemistry, Heidelberg University, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
The design of metalloproteins allows us to better understand metal complexation in proteins and the resulting function. In this study, we incorporated a Cu-binding site into a natural protein domain, the 58 amino acid c-Crk-SH3, to create a miniaturized superoxide dismutase model, termed SO1. The resulting low complexity metalloprotein was characterized for structure and function by circular dichroism and UV spectroscopy as well as EPR spectroscopy and X-ray crystallography.
View Article and Find Full Text PDFACS Omega
January 2025
Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia.
Carbon dots (CDs) are emerging novel fluorescent sensing nanomaterials owing to their tunable optical properties, biocompatibility, and eco-friendliness. Herein, we report a facile one-pot hydrothermal route for the synthesis of highly green fluorescent CDs using gallic acid (GA) as a single carbon source in ,-dimethylformamide (DMF) solvent, which serves as a nitrogen source and reaction medium. The optical properties of the synthesized GA-DMF CDs were systematically characterized by using UV-vis and photoluminescence spectroscopy, revealing strong green fluorescence.
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