Co-Crystal of Phenylsuccinic Acid and 4,4'-Bipyridine: Synthesis,Characterization, Crystal Structure,and Supramolecular Interactions

Crystallography Reports - A new co-crystal compound of 4,4'-bipyridine and phenylsuccinic acid was synthesized and characterized by elemental analysis, infrared and ultraviolet–visible...     

Nano NiO/AlMCM‐41, a green synergistic,highly efficient and recyclable catalyst for the reduction of nitrophenols

Highly ordered mesoporous molecular sieves AlMCM‐41 and a new NiO/AlMCM‐41 nanocomposite were synthesized using a sol–gel method. Fourier transform infrared (FT‐IR) spectroscopy, X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDX), and N₂ adsorption desorption analyses were used to examine the structure, morphology, size and phase composition of the synthesized NiO/AlMCM‐41 nanocomposites. AlMCM‐41 embedded with NiO nanoparticles was subsequently prepared using different nickel loadings in a direct synthetic route. The results show the successful deposition of NiO nanoparticles onto the framework of AlMCM‐41. AlMCM‐41 provides enormous benefits such as environmentally safe, economic viability and porosity when used as support for NiO nanoparticles. The excellent catalytic activities of AlMCM‐41 and NiO/AlMCM‐41 were investigated for the reduction of nitrophenols (4‐NP, 2‐NP) to aminophenols (4‐AP, 2‐AP) in water at ambient temperature. The best observed performance of reduction of NP with 100% conversion into analogous amino derivatives occurred within 6 min with an estimated rate constant of 0.46 min^?1. The efficiency of reduction was observed to increase as a function of NiO enrichment. The NiO/AlMCM‐41 nanocomposite could be recycled and reused up to five times without noticeable change in its structure and activity. These properties make NiO/AlMCM‐41 nanocomposite an ideal platform to study various heterogeneous catalytic processes which can have application in purification, catalysis, sensing devices, and green chemistry.     

Health risk assessment of neonicotinoid insecticide residues in pistachio using a QuEChERS-based method in combination with HPLC-UV

There is an increasing need to address the potential risks arising from combined exposures to multiple residues from pesticides in the diet. Pesticide residue-related pollution is a problem that arises because of the increased use of pesticides in agriculture to meet the growing demands of food production. In this study, pesticide residue data were obtained based on an optimized extraction method. For this purpose, we established a method based on qu ick, e asy, ch eap, e ffective, r ugged, and s afe (QuEChERS) extraction for simultaneous determination of imidacloprid (IMI) and acetamiprid (ACT) in pistachio nuts. The parameters influencing the QuEChERS method were the sample-to-water ratio and adsorbent amounts. As a result, both were optimized to improve the recovery of the analytes as well as the clean-up efficiency of the pistachio matrix. Our results indicated that a freeze-out step and use of primary and secondary amines as an adsorbent led to much cleaner chromatograms with lower baseline drift, without using graphitized carbon black and C₁₈-based adsorbent, which reduced both cost and time of analysis. Following extraction, the pesticide residues were separated and quantified by reverse-phase HPLC. For validation purposes, recovery studies were carried out using a concentration range from 20 to 2500 μg/L at nine levels. The suitable linearity, precision, and accuracy were obtained with HPLC–UV with recoveries of 70.37%–89.80% for IMI and 81.05%–113.57% for ACT, with relative standard deviations <12%. The validated method was successfully applied to the analysis of pistachio samples collected from a field trial to estimate maximum residue limits. There was no significant health risk for consumers via pistachio consumption.     

Dichloroimidazolidinedione-activated one-pot Suzuki–Miyaura cross-coupling of phenols

The first general method for the Suzuki-type cross-coupling of phenols with aryl boronic acids using dichloroimidazolidinedione (DCID) as a new reagent is presented. In the presence of DCID and Pd/metal–organic framework (MOF), coupling of aryl boronic acids with a wide range of phenols, was carried out smoothly in tetrahydrofuran (THF) at reflux conditions to afford the cross-coupling products in good to excellent yields. The structures of all compounds were corroborated by ¹H- and ¹³C-NMR. A plausible mechanism for this type of reaction is proposed.     

Ultrasonic‐assisted synthesis of supramolecular copper (II) complex a precursor for the preparation of octahedron Cu2O nanoparticles applicable in the adsorption and photodegradation of Rhodamine B

A copper (II) supramolecular coordination complex formulated as [Cu₂(μ‐ox)₂(pyz)₃]_n ( 1 ), (pyz = pyrazine and ox = oxalate) has been synthesized under ultrasound irradiation. 1 was characterized using various techniques such as elemental analyses, Fourier‐transform infrared spectroscopy (FT‐IR), ultraviolet–visible spectroscopy (UV–Vis), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and single crystal X‐ray diffraction (SC‐XRD). A detailed magnetic characterization of complex 1 has been carried by vibrating sample magnetometer (VSM). The M‐H hysteresis loop of 1 revealed a weak ferromagnetic behavior with the highest magnetization of 0.0123 emu/g at room temperature. Compound 1 was used as an inorganic precursor to prepare Cu₂O nanoparticles through thermal decomposition at 600 °C. The obtained Cu₂O has been characterized using Fourier transform infrared spectroscopy (FT‐IR), X‐ray powder diffraction (XRPD) and scanning electron microscopy (SEM). The results of SEM showed octahedron Cu₂O nanoparticles with the edge lengths from 5–80 nm. Also, the adsorption ability and the photocatalytic activity of octahedral Cu₂O nanoparticles in the removal of rhodamine B (RB) have been investigated. The results showed that the obtained octahedral Cu₂O nanoparticles are effective in adsorption and degradation of rhodamine B from contaminated water sources. The maximum adsorption capacity and degradation efficiency of Cu₂O nanoparticles were 83.3 mg/g and 91.7%, respectively. It was also found that in comparison with the commercial Cu₂O, our fabricated Cu₂O nanoparticles exhibit higher catalytic activity.     

Two-proton radioactivity of 45Fe

The decay of the extremely neutron-deficient isotope ⁴⁵Fe has been studied by using a new type of gaseous detector in which a technique of optical imaging is used to record tracks of charged particles. The two-proton radioactivity and the $ \beta$ -decay channels were clearly identified. For the first time, the angular and energy correlations between two protons emitted from the ⁴⁵Fe ground state were measured. The obtained results were confronted with predictions of a three-body model.     

Synthesis and Reactivity of Functionalized Binary and Ternary Thiometallate Complexes [(RT)4S6], [(RSn)3S4]2−, [(RT)2(CuPPh3)6S6], and [(RSn)6(OMe)6Cu2S6]4− (R=C2H4COOH,CMe2CH2COMe; T=Ge,Sn)

Caged chalcogens : A series of novel, functionalized T_nS_m cages (T=Ge, Sn; n/m=4:6, 3:4) with terminal COO(H) or COMe groups were synthesized and show further reactivity toward Cu^I complexes (an example of which is shown here) and to hydrazines. This led to the generation of functionalized Cu/T/S clusters or the formation of Schiff bases at the C?O groups, respectively, with or without further fragmentation of the T/S core.

     

Phase selective amphiphilic supergelators for oil spill solidification and dye removal

Four glucose-based phase selective organogelators were designed and synthesized from low-cost and readily available starting materials. Our rapid acting supergelators were able to gelate a wide spectrum of solvents in mono- or biphasic systems, at very low concentration. They were shown to solidify oil spills at room temperature, in the form of a semi-dried gel, within 90 min. It was also revealed that their n-butanol gel could effectively absorb pollutant dyes from aqueous media. As novel smart materials, these gelators are potentially applicable to remove contaminants including aromatic solvents, oil spills, and toxic dyes from water resources. The gelators have been well characterized using spectroscopic, microscopic, and rheological studies.