Analytical Chemistry
DOI: 10.1021/acs.analchem.3c04819
Ligand‐field effect to harness the magnetic anisotropy in a series of mixed valence Co (III)–Co (II) dinuclear complexes
Three Co (III)–Co (II) mixed valence dinuclear complexes were synthesized and characterized using various techniques. These complexes exhibited elongated octahedral geometry around Co (II) ion, significant magnetic anisotropy, and field-induced single-molecule magnet behavior with magnetization relaxation through Raman, Orbach, and direct processes. The analysis of magnetic properties was complemented by theoretical calculations.
Three mixed valence dinuclear Co (III)–Co (II)-based complexes having general formulae of [CoIICoIII (HL2)2(L1)] [L1H = 2-hydroxy-1-naphthaldehyde (1), o-vanillin (2), and salicylaldehyde (3)] have been synthesized successfully using Schiff base (LH4) ligand. The complexes were characterized by single-crystal XRD, powder XRD, IR, and UV–Vis analyses. The CoII ion with elongated octahedral geometry conferred significant magnetic anisotropy with D values being 64.0(8), 71.1(7), and 52.1(3) cm−1 for 1, 2, and 3, respectively. These complexes exhibited single-molecule magnet behavior with magnetic relaxation occurring mainly through Raman for 1 and 3 whereas direct and Raman for complex 2. The analysis of the static and dynamic magnetic properties was further supported by theoretical calculations using CASSCF/DLPNO-NEVPT2.
Novel Triazole‐Containing “Dipeptides”: Synthesis, Molecular Docking And Analgesic Activity Studies
Dipeptides of a new structure based on β-triazolalanines and (L)-α-amino acids were synthesized and optimal conditions were developed that ensure both chemical and optical purity of the final products. Molecular docking was carried out and possible intermolecular interactions of dipeptides with potential targets were established. Based on these studies, the analgesic property of chosen dipeptides was studied and it was found that some compounds possess revealed antinociceptive activity in the tail-flick test.
[ASAP] Overlaid Lateral Flow Immunoassay for the Simultaneous Detection of Two Variant-Specific SARS-CoV-2 Neutralizing Antibodies
Analytical Chemistry
DOI: 10.1021/acs.analchem.3c05144
Sonocatalysis green synthesis of indeno[1,2‐b]indolone derivatives using CuFe2O4@CS‐SB nanocomposite as a reusable catalyst under mild conditions
![Sonocatalysis green synthesis of indeno[1,2-b]indolone derivatives using CuFe2O4@CS-SB nanocomposite as a reusable catalyst under mild conditions](https://onlinelibrary.wiley.com/cms/asset/3ebf6088-deaf-4de4-8de2-82fc71c87485/aoc7406-toc-0001-m.png)
In this literature, the synthesis of indeno[1,2-b]indolone from starting materials of ninhydrin, derivatives of aniline, and dimedone by using copper ferrite anchored to chitosan bearing Schiff base (CuFe2O4@CS-SB) as a catalyst in water solvent under ultrasound irradiation was described.
In this literature, the synthesis of indeno[1,2-b]indolone from starting materials of ninhydrin, derivatives of aniline, and dimedone by using copper ferrite anchored to chitosan bearing Schiff base (CuFe2O4@CS-SB) as a catalyst in water solvent under ultrasound irradiation was described. This catalyst was designed, fabricated, and characterized by the FT-IR, 1H NMR, XRD, SEM, TGA, mapping scan, EDX, and BET techniques. This prepared acidic, effective heterogeneous catalyst catalyzed green synthesis of indeno-indolone derivatives in a very short reaction times between 1 and 7 min with excellent yields between 95% and 99%. Also, the FT-IR, 1H NMR, and melting point analyses are used to identify the synthesis of the indolones as organic products.
Binary NiCu oxide nanoparticles onto graphite as promoting nanocatalysts for ethanol electro‐oxidation process
Enhanced activity of NiCuO/T nanocatalysts was measured towards ethanol electro-oxidation process.
A facile and reduced cost fabrication protocol was followed to have a series of nickel oxide nanospecies onto graphite support with introducing varied copper oxide wt.% values (NiCuO/T). The co-precipitation of metallic hydroxide particles onto carbonaceous surfaces and their subsequent burning at 400°C were sufficient to prepare mixed transition metal oxides. Suitable analysis tools were exploited to fully characterize the obtained nanopowders using scanning electron microscopy, transmission electron microscopy, X-ray diffraction spectroscopy, X-ray photoelectron spectroscopy, and energy dispersive X-ray analysis. Outstanding performances of the formed nanocatalysts for catalyzing ethanol electro-oxidation reaction were measured especially in presence of 15 wt.% copper oxide content. The onset potential (Eonset) value of alcohol oxidation process was negatively shifted at dispersed NiO nanoparticles onto graphite after doping with copper oxide nanospecies. This promoted activity of prepared nanomaterials could be explained by their increased active sites when binary metallic oxides were incorporated. Electrochemical impedance spectroscopy studies demonstrated much lowered resistances in alkaline solution containing ethanol molecules to ascertain the enhanced behavior of NiCuO/T nanocatalysts. Moreover, their good stability attitude encouraged the application of doped nanomaterials with copper oxide for fuel cells application.
Efficient Transferase Engineering for SAM Analog Synthesis from Iodoalkanes
S-Adenosyl-l-methionine (SAM) is an important cosubstrate in various biochemical processes, including selective methyl transfer reactions. Simple methods for the (re)generation of SAM analogs could expand the chemistry accessible with SAM-dependent transferases and go beyond methylation chemistry. Here we present an efficient enzyme engineering strategy to synthesize different SAM analogs from “off-the-shelf” iodoalkanes through enzymatic alkylation of S-adenosyl-l-homocysteine (SAH). This was achieved by mutating multiple hydrophobic and structurally dynamic amino acids simultaneously. Combinatorial mutagenesis was guided by the natural amino acid diversity and generated a highly functional mutant library. This approach increased the speed as well as the scale of enzyme engineering by providing a panel of optimized enzymes with orders of magnitude higher activities for multiple substrates in just one round of enzyme engineering. The optimized enzymes exhibit catalytic efficiencies up to 31 M-1s-1, convert various iodoalkanes, including substrates bearing cyclopropyl or aromatic moieties, and catalyze S-alkylation of SAH with very high stereoselectivities (>99% de). We further report a high throughput chromatographic screening system for reliable and rapid SAM analog analysis. We believe that the methods and enzymes described herein will further advance the field of selective biocatalytic alkylation chemistry by enabling SAM analog regeneration with “off-the-shelf” reagents.
Synthesis of Ferrocenyl Boranes and their Application as Lewis Acids in Epoxide Rearrangements
A series of substituted ferrocenyl boranes and boronic acids were synthesized. The oxidation to the corresponding ferrocenium derivatives provides access to strong Lewis acids as characterized by computational methods. The ferrocenium derivatives were active catalysts for the Lewis acid mediated Meinwald epoxide rearrangement and yielded predominantly the aldehydes as kinetic products.
Abstract
A series of substituted ferrocenyl boron derivatives was synthesized. The oxidation of the ferrocenyl unit resulted in a significant increase of the boron-centered Lewis acidity. The neutral and cationic Lewis acids were characterized by NMR spectroscopy, crystal structure analysis and by computational methods. The new Lewis acids were then applied in the Meinwald rearrangement of epoxides, predominantly furnishing aldehydes as the kinetic products.
[ASAP] Development of High-Performance and Multifunctional Nanoparticles Powered the Integrated Diagnosis and Treatment of Escherichia coli O157:H7
Analytical Chemistry
DOI: 10.1021/acs.analchem.3c05519
Facile Preparation of Impalement Resistant, Mechanically Robust and Weather Resistant Photothermal Superhydrophobic Coatings for Anti‐/De‐icing
Photothermal superhydrophobic coatings hold great promise in addressing the limitations of conventional superhydrophobic anti-icing coatings. However, developing such coatings with excellent impalement resistance, mechanical robustness and weather resistance remains a significant challenge. Here, we report facile preparation of robust photothermal superhydrophobic coatings with all the above advantages. The coatings were prepared by spraying a dispersion consisting of fluorinated silica nanoparticles, a silicone-modified polyester adhesive and photothermal carbon black nanoparticles onto Al alloy plates followed by thermal curing. Thermal curing caused migration of perfluorodecyl polysiloxane from within the coatings to the surface, effectively maintaining a low surface energy despite the presence of the adhesive. Therefore, combined with the hierarchical micro-/nanostructure, dense yet rough nanostructure, adhesion of the adhesive and chemically inert components, the coatings exhibited remarkable superhydrophobicity, impalement resistance, mechanical robustness and weather resistance. Furthermore, the coatings demonstrated excellent photothermal effect even in the -10 °C, 80% relative humidity and weak sunlight (0.2 sun) environment. Consequently, the coatings showed excellent passive anti-icing and active de-icing performance. Moreover, the coatings have good generalizability and scalability. We are confident that this study will accelerate the practical implementation of photothermal superhydrophobic coatings.