Synthesis and Optical Study of Sensitive and Selective Calix[4] Based Cu2+ Ion Detection Probes

Russian Journal of General Chemistry - Naked-eye colored chemo dosimeters based on symmetrical calix[4]azo dye conjugates A1–3 are synthesized and characterized. Calix[4]azo dye conjugates...     

Preparation of novel hybrid nanomaterials based on LaFeO3 and phosphotungstic acid as a highly efficient magnetic photocatalyst for the degradation of methylene blue dye solution

Novel magnetic hybrid nanomaterials 1 (LaFeO₃.Fe₃O₄@SiO₂-NH₂/PW₁₂) were synthesized by supporting phosphotungstic acid (H₃PW₁₂O₄₀; PW₁₂) on LaFeO₃.Fe₃O₄ nanomaterials through sono-assisted method. The synthesized nanomaterials were fully characterized by using FT-IR, XRD, UV–vis, BET-BJH, VSM, SEM, and TEM analyses. FT-IR, XRD, and UV–vis confirmed successful synthesis of nanomaterials. The SEM and TEM images revealed spherical morphology with core-shell structure for hybrid nanomaterials 1 . VSM results confirmed the magnetic property of hybrid nanomaterials 1 and suggested it as easily recyclable photocatalyst for removal of organic dyes from aqueous solution. The photocatalytic activity of hybrid nanomaterials 1 has been studied over the degradation of methylene blue (MB) and methyl orange (MO) solution under UV–vis light irradiation. Importantly the hybrid nanomaterials 1 showed outstanding degradation efficiency for MB solution in comparison with bare LaFeO₃.Fe₃O₄ and PW₁₂. The photocatalytic activity was enhanced mainly due to the high efficiency in separation of electron–hole pairs induced by the remarkable synergistic effects of LaFeO₃.Fe₃O₄ and PW₁₂ semiconductors. After the photocatalytic reaction, the nanocomposite can be easily separated from the reaction solution and reused several times without loss of its photocatalytic activity. Trapping experiments indicated that hole (h_VB⁺) and ^•OH radicals were the main reactive species for dye degradation in the present photocatalytic system. On the basis of the experimental results and estimated band gaps, the mechanism for the enhanced photocatalytic activity was proposed.     

A Green Strategy to Prepare Warfarin‐like Compounds Catalyzed by Zirconium Oxychloride

A one‐pot, three‐component synthesis of warfarin‐like compounds from the reaction of benzamide, aryl glyoxal and 4‐hydroxycoumarin is described. Zirconium oxychloride octahydrate catalyzed the reactions efficiently under solvent‐free conditions to yield desired products in good yields.     

NHC-assisted Ni(II)-catalyzed acceptorless dehydrogenation of amines and secondary alcohols

A novel catalytic system including NiCl₂-NHC ligand precursor has been developed for the preparation of imines from amines and ketones from alcohols. Owing to the acceptorless dehydrogenation pathway for this reaction, the hydrogen gas is liberated as a by-product. The active catalyst is generated in situ by the reaction of nickel (II) chloride, bis (imidazolium) chlorides and potassium tert-butoxide. The products were obtained in good to excellent yields and a wide variety of amines and ketones were applied successfully in this protocol.     

Synthesis,Characterization and Fluorescence Properties of Novel Porous Fe/ZnO Nano-Hybrid Assemblies by Using Berberis thunbergii Extract

Journal of Fluorescence - In this work, novel Fe/ZnO nanocomposites (NCs) and Fe nanoparticles loaded onto porous ZnO nanostructures have been synthesized via a simple biotechnological route by...     

Selective and Sensitive Two New Macroacyclic Schiff base Fluorescent Turn-Off Receptors for Fe3+, DFT Calculation and Their Antibacterial Activity

Two new Macroacyclic Schiff base chemosensors (L₁ and L₂) were synthesized by the one pot condensation reaction of 2-[3-(2-formyl phenoxy)propoxy]benzaldehyde and aminophenol in a 1:2 molar ratio and were characterized by IR, NMR spectroscopy. Both Schiff bases displayed high selectivity and sensitivity towards Fe³⁺ over other metal ions in H₂O-DMF solution (Ag⁺,Cu²⁺, Ni²⁺, Zn²⁺, Mg⁺², Mn⁺², Pb⁺², Co⁺², Hg⁺², Cr⁺³, Na⁺, Ba⁺² and Cd²⁺) due to their structure including oxygen donor atoms. The test results showed fluorescence quenching of the fluorophores when Fe³⁺ was bound to the recognition units. From test results, a high selectivity for Fe³⁺ were discovered in this type of sensors, especially, the probe based on 2-aminophenol exhibited more significant quenching in fluorescence intensity compared with 4-aminophenol-based due to its rigidity structure. In addition, the structure of ligands and their antibacterial properties was investigated.     

Miniaturized integrated evanescent field IR-absorption sensor: Design and experimental verification with deteriorated lubrication oil

In industry, a vast variety of processes can be optimized by means of online measurement of chemical properties of fluids in order to reduce costs of maintenance or increase productivity as well as production quality. Since the absorption measurement in the mid-IR-region is a powerful method to determine the chemical composition of fluids, we propose a fully integrated absorption sensor based on IR-absorption in the evanescent field region of an integrated mono-mode waveguide utilizing thermally generated and detected IR-radiation. For the coupling, two grating couplers are employed, which couple broadband thermal IR-radiation into the waveguide and the attenuated IR-radiation towards a thermal IR-detector, respectively. To achieve a spectroscopic measurement, we utilize the dispersive feature of the grating coupler, which couples the IR-beams out of the waveguide at angles depending on the frequency. We report on the design of the fully integrated infrared absorption sensor, which is capable to determine chemical properties of, e.g., lubrication oil by investigating infrared absorption. Beside the theory related to an optimum design of the mono-mode waveguide, we discuss the applicability of the proposed concept to the monitoring of deterioration of lubrication oil.     

The numerical simulation and sensitivity analysis of a non-Newtonian fluid flow inside a square chamber exposed to a magnetic field using the FDLBM approach

Journal of Thermal Analysis and Calorimetry - This paper simulated the free convective heat transfer (CHT) and generation of entropy (GOE) of a non-Newtonian fluid (NNF) in a square chamber using...