Spectrochim Acta A Mol Biomol Spectrosc
Department of Chemistry, Faculty of Science, Al-Azhar University, Cairo, Egypt. Electronic address:
Published: October 2018
Copper is an essential element in some biological processes in organisms, so it was important to find ways to identify trace amounts of it. Minimal amounts of copper ions can be determined in aqueous solutions in the spectrophotometric method suggested in this study. The method depends on the reaction between Cu(II) and Amaranth dye at the pH 6.0. The gradual disappearance of Amaranth colour at 520 nm occurring with an increase of Cu(II) concentration from 0.13 up to 2.0 μg cm. The molar absorptivity coefficient and Sandell's sensitivity of the complex are found to be 0.94 × 10 L mol cm, 6.8 ng cm respectively. The advantages of this method are simple, selective, and highly sensitive. The method was used for determination of copper ions in aqueous solutions containing several metal ions, where excellent agreements between reported and obtained results were achieved in aqueous solutions containing copper metal ions only. The postulated method is in an excellent agreement with the determination of Cu(II) ion concentrations by atomic absorption spectroscopy (AAS). The interference was studied to determine the copper metal ions concentration, and do not interfere with eleven of other metal ions.
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http://dx.doi.org/10.1016/j.saa.2018.06.014 | DOI Listing |
Inorg Chem
January 2025
Department of Chemistry, University of Patras, Patras 265 04, Greece.
A new [DyBiOCl(saph)] () Werner-type cluster has been prepared, which is the first Dy/Bi polynuclear compound with no metal-metal bond and one of the very few Ln-Bi (Ln = lanthanide) heterometallic complexes reported to date. The molecular compound has been deliberately transformed to its 1-D analogue [DyBiO(N)(saph)] () via the replacement of the terminal Cl ions by end-to-end bridging N groups. The overall metallic skeleton of (and ) can be described as consisting of a diamagnetic {Bi} unit with an elongated trigonal bipyramidal topology, surrounded by a magnetic {Dy} equilateral triangle, which does not contain μ-oxo/hydroxo/alkoxo groups.
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January 2025
State Key Laboratory of Organometallic Chemistry and Shanghai Hongkong Joint Laboratory in Chemical Synthesis, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032 (China).
Singly occupied molecular orbital (SOMO) activation of in situ generated enamines has achieved great success in (asymmetric) α-functionalization of carbonyl compounds. However, examples on the use of this activation mode in the transformations of other functional groups are rare, and the combination of SOMO activation with transition metal catalysis is still less explored. In the area of deoxygenative functionalization of amides, intermediates such as iminium ions and enamines were often generated in situ to result in the formation of α-functionalized amines.
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January 2025
Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, 1098 XH Amsterdam, Netherlands.
We present the synthesis, structural analysis, and remarkable reactivity of the first carbon nanohoop that fully incorporates ferrocene in the macrocyclic backbone. The high strain imposed on the ferrocene by the curved nanohoop structure enables unprecedented photochemical reactivity of this otherwise photochemically inert metallocene complex. Visible light activation triggers a ring-opening of the nanohoop structure, fully dissociating the Fe-cyclopentadienyl bonds in the presence of 1,10-phenanthroline.
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January 2025
Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China.
ConspectusThe Mannich reaction, involving the nucleophilic addition of an enol(ate) intermediate to an imine or iminium ion, is one of the most widely used synthetic methods for the synthesis of β-amino carbonyl compounds. Nevertheless, the homo-Mannich reaction, which utilizes a homoenolate intermediate as the nucleophilic partner and provides straightforward access to the valuable γ-amino carbonyl compounds, remains underexplored. This can be largely attributed to the difficulties in generation and manipulation of the homoenolate species, despite various homoenolate equivalents that have been developed.
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January 2025
Materials Genome Institute, Shanghai University, Shanghai, 200444, China.
The local structure plays a crucial role in oxygen redox reactions, which boosts the capacity of layered oxide cathodes for sodium-ion batteries. While studies on local structural ordering have primarily focused on the intra-layer ordering, there has been limited research on the inter-layer stacking for the layered cathode materials for sodium-ion batteries. In this work, the impact of the intra-layer and inter-layer local structural regulation on anionic kinetics and the structure stability are explored through experimental analysis and theoretical calculations.
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