Sol–gel auto-combustion synthesis,structural and enhanced magnetic properties of Ni substituted nanocrystalline Mg–Zn spinel ferrite

Nanocrystalline arrays of Ni²⁺ substituted Mg–Zn spinel ferrite having a generic formula Mg_0.7−xNi_xZn_0.3Fe₂O₄ (x=0.0, 0.2, 0.4 and 0.6) were successfully synthesized by sol–gel auto-combustion technique. The fuel used in the synthesis process was citric acid and the metal nitrate-to-citric acid ratio was taken as 1:3. The phase, crystal structure and morphology of Mg–Ni–Zn ferrites were investigated by X-ray diffraction, scanning electron microscopy, and Fourier transformer infrared spectroscopy techniques. The lattice constant, crystallite size, porosity and cation distribution were determined from the X-ray diffraction data method. The FTIR spectroscopy is used to deduce the structural investigation and redistribution of cations between octahedral and tetrahedral sites of Mg–Ni–Zn spinel structured material. Morphological investigation suggests the formation of grain growth as the Ni²⁺ content x increases. The saturation magnetization and magneton number were determined from hysteresis loop technique. The saturation magnetization increases with increasing Ni²⁺ concentration ‘x’ in Mg–Zn ferrite.     

One-Pot Multicomponent Synthesis,Molecular Docking,and In Vitro Antibacterial Activities of 1-{(Aryl)[(5-methyl-1,3-thiazol-2-yl)amino]methyl}naphthalen-2-ol

Russian Journal of Organic Chemistry - A series of new Betti bases, 1-{(aryl)[(5-methyl-1,3-thiazol-2-yl)amino]methyl}naphthalen-2-ols, have been synthesized via one-pot three-component reaction of...     

Sensitive HPTLC Method for Monitoring Dissolution Profiles of Diclofenac from Different Tablets Containing Combined Diclofenac and Acetaminophen

JPC – Journal of Planar Chromatography – Modern TLC - Two fundamentally different analytical methods have been validated and used to monitor release of diclofenac and acetaminophen...     

Microwave Assisted,Solvent-Free, “Green” Synthesis of Novel Indole Analogs as Potent Antitubercular and Antimicrobial Agents and Their Molecular Docking Studies

A rapid, efficient and environmentally benign synthesis of novel indole analogs bearing thiazolidinone attached to substituted thiazolyl coumarin scaffolds are synthesized. Conventional and microwave-assisted (MW) approaches are studied. Structures of the products are confirmed by FT-IR, NMR (¹H and ¹³C) and Mass spectra. The in vitro antitubercular and antimicrobial activities are evaluated. Several screened compounds demonstrate promising anti-TB and antimicrobial properties. The structure activity relationship (SAR) study reveal that the compounds containing halogens are most potent. Docking of the potent compounds inside the active site of a target enzyme mycobacterial enoyl reductase (InhA)(PDB code 4TZK) is performed.

     

Solvent-free synthesis of propargylamines via A3 coupling reaction and organic pollutant degradation in aqueous condition using Cu/C catalyst

The present report focuses on the efficient and operationally simple synthesis of biomass-derived carbon as support to immobilize copper particles as a catalyst for the one-pot synthesis of propargylamines from furfural via the A³ coupling reaction. This new catalyst showed remarkable catalytic performance leading to a 97% yield within 5 h at 80 °C using 5 mg (0.0022 mmol Cu) of Cu/C catalyst under solvent-free condition. Moreover, nitro-substituted compounds such as 4-nitrophenol (4-NP) are highly toxic and not easily degradable. Hence, a quick and effective method is required to neutralize these toxic compounds. The synthesized active support Cu/C catalyst having various electron-donating groups containing small amounts of Cu plays an essential role in the catalytic reduction of 4-NP (0.1 g). Using only 3 mg (0.0013 mmol Cu) of Cu/C catalyst and NaBH₄ (10 mmol), a 99% yield (100% selectivity) in the aqueous condition at 25 °C was achieved. The catalytic reduction follows the pseudo-first-order kinetics with reaction rate constant of 0.028 s⁻¹. Moreover, results demonstrate that the Cu/C catalyst has superior catalytic activity due to the presence of electron-donating molecules such as O, S, and N atoms, which enable synergistic effect in enhancing the overall catalytic performance. Notably, the recoverability and recyclability of the synthesized catalyst were evaluated for up to four cycles, which confirmed its stability in these cycles.     

Rheology and microstructural studies of regenerated silk fibroin solutions

Regenerated silk fibroin solutions (RSF) are produced by dissolving degummed silk fibers in water. We have observed that RSF solutions at a concentration less than 15 % by weight exhibit an unusual gel-like response in conventional shear rheology measurements. At higher concentrations, the response is predominantly viscous (or liquid-like). We have probed this counterintuitive behavior of silk fibroin solutions by using microrheology, and interfacial rheometry. Scattering techniques were also used to understand the microstructure of RSF solutions as a function of the concentration. Our studies suggest that the gel-like response of the RSF solution may result from the formation of an interfacial film at the air–solution interface, which dominates the bulk rheological response.     

Measurement of photoexcitation cross-sections of uranium by saturation method

We report the measurement of photoexcitation cross-sections of three first-step uranium transitions (0 → 16900.38 cm ⁻¹, 0 → 17361.89 cm ⁻¹ and 620 → 17361.89 cm ⁻¹) using saturation method. These measurements were performed on a resonance ionization mass spectrometry (RIMS) set-up consisting of Nd:YAG-pumped dye lasers, a reflectron time-of-flight mass spectrometer and high-temperature atomic vapour source. The uranium vapours were excited and photoionized by two-colour, three-photon photoionization scheme using Nd:YAG-pumped dye laser system. The resultant photoion signal was monitored as a function of dye laser fluence used for first step excitation to measure the excitation cross-section values. A new approach was adopted to overcome the large uncertainties associated with such measurements. With this approach the cross-section of transitions whose value is already reported in the literature was measured as a bench mark. By normalizing the measured value to the reported value, a scaling factor was derived. This scaling factor was used to scale up the cross-section values of other transitions measured by this method.     

Acyl metalloids: conformity and deviation from carbonyl reactivity

Once considered as mere curiosities, acyl metalloids are now recognized for their utility in enabling chemical synthesis. This perspective considers the reactivity displayed by acylboron, -silicon, -germanium, and tellurium species. By highlighting the role of these species in various transformations, we demonstrate how differences between the comprising elements result in varied reaction outcomes. While acylboron compounds are primarily used in polar transformations, germanium and tellurium species have found utility as radical precursors. Applications of acylsilanes are comparatively more diverse, owing to the possibility to access both radical and polar chemistry.

Originally considered as fundamental curiosities, acyl metalloids have proven to be useful tools in synthesis. This perspective aims to highlight the modes of reactivity accessible to boron, silicon, germanium and tellurium species.     

Determination of gatifloxacin and ornidazole in tablet dosage forms by high-performance thin-layer chromatography.

A simple and sensitive high-performance thin-layer chromatography (HPTLC) method has been developed for the quantitative estimation of gatifloxacin and ornidazole in its combined dosage forms. Gatifloxacin and ornidazole were chromatographed on silica Gel 60 F(254) TLC plate using n-butanol:methanol:ammonia (6 M) (8:1:1.5 v/v) as the mobile phase and scanned at 302 nm using a Camag TLC Scanner 3. The R(f) value of gatifloxacin and ornidazole was found to be 0.21 +/- 0.02 and 0.76 +/- 0.04, respectively. The linearity of gatifloxacin and ornidazole were in the range of 100 - 500 ng/spot and 250 - 1250 ng/spot, respectively. The limit of detection was found to be 40 ng/spot for gatifloxacin and 100 ng/spot for ornidazole. The proposed method was applied for the determination of gatifloxacin and ornidazole in combined dosage forms.     

Quantification of desmosine and isodesmosine using MALDI-ion trap tandem mass spectrometry

Analytical and Bioanalytical Chemistry - Desmosine (Des) and isodesmosine (Isodes), cross-linking amino acids in the biomolecule elastin, may be used as biomarkers for various pathological...