Synthesis of diaryl sulfides via nickel ferrite‐catalysed C─S bond formation in green media

NiFe₂O₄ magnetic nanoparticles (MNPs) were synthesized, characterized and applied as an air‐stable, inexpensive and magnetically separable nanocatalyst for the synthesis of structurally diverse sulfides. Efficient methodologies were developed for the synthesis of unsymmetric diaryl sulfides via odourless and one‐pot reactions of triphenyltin chloride/S₈ or arylboronic acid/S₈ as thiolating agents with aryl halides or nitroarenes as starting materials in the presence of base (K₂CO₃ or NaOH) and NiFe₂O₄ MNPs as a catalyst in water or poly (ethylene glycol) as solvent at 80–110 °C. Free from ligand and the unpleasant smell of thiols and with the use of magnetically reusable nanocatalyst, green solvents and commercially available and cheap sulfur source and starting materials, these methods are more eco‐friendly and practical than available protocols for the synthesis of sulfides.     

Preparation of bismuth sulfide nanoparticles as targeted biocompatible nano-radiosensitizer and carrier of methotrexate

In this study, Bi₂S₃@BSA–Bio–MTX nanoparticles (NPs) were synthesized for the first time by bovine serum albumin (BSA)-mediated biomineralization (Bi₂S₃@BSA NPs) followed by covalent bonding of biotin (Bio) and methotrexate (MTX) on the surface of the Bi₂S₃@BSA NPs via carbodiimide chemistry. The synthesized NPs were globular and exhibited uniform morphology with a hydrodynamic diameter of 107.6 ± 6.81 nm (mean ± standard deviation) and zeta potential of −20.9 ± 2.18 mV. Drug release from Bi₂S₃@BSA–Bio–MTX NPs indicated an enzyme-dependent release pattern. The in vitro biocompatibility of NPs was confirmed by investigating their cytotoxicity against the HEK-293 cell line and hemolysis assay test, whereas the in vivo biocompatibility of the NPs was evaluated and confirmed by the lethal dose 50 (LD₅₀) test. To evaluate the in vitro anticancer activity of the functionalized NPs and MTX, their cytotoxic effects was assessed against 4T1 cancer cells by 5-dimethylthiazol-z-yl)-2,5-diphenyltetrazolium bromide (MTT) assay with and without X-ray radiation. Results showed that Bi₂S₃@BSA–Bio–MTX NPs have excellent anticancer activity, especially following X-ray radiation.     

Preparation and characterization of Cu (II) Schiff base complex functionalized boehmite nanoparticles and its application as an effective catalyst for oxidation of sulfides and thiols

The synthesis, characterization, and evaluation of a Schiff base Cu (II) complex functionalized boehmite nanoparticles (Cu-complex-boehmite) as a new catalyst for oxidation of sulfides and thiols in the presence of hydrogen peroxide with complete selectivity and high conversion under solvent-free and mild reaction conditions were reported. Characterization of the catalyst was performed with various physicochemical methods. This effective catalyst was evaluated in terms of activity and reusability. It indicated high catalytic activity, good recoverability and reusability, and supplied the corresponding products in high yields and short reaction times. In addition, it shows notable advantages such as simplicity of operation, heterogeneous nature, easy work up, and it could be used at least eight times with no significant loss of its activity.     

Effect of textural characteristics on the catalytic performance of supported KCoMoS2 in the synthesis of higher alcohols from syngas

The influence of textural characteristics on the catalytic performance of supported KCoMoS₂ catalysts was explored to provide essential information for the design of better catalysts for the synthesis of higher alcohols (C₁–C₅) from syngas. Syngas conversion was carried out over KCoMoS₂ catalysts supported on various mesoporous (alumina and carbon-coated alumina) and microporous (two types of powdered activated carbons) materials. The experimental results show that catalysts supported over microporous materials exhibit higher catalytic activity in HAS from syngas than catalysts based on mesoporous materials.     

Green route for selective gram‐scale oxidation of sulfides using tungstate/triazine‐based ionic liquid immobilized on magnetic nanoparticles as a phase‐transfer heterogeneous catalyst

Tungstate ions were successfully loaded onto triazine‐based ionic liquid‐functionalized magnetic nanoparticles through an anion exchange process. The use of triazine core for creating ionic liquid led to the immobilization of high amounts of WO₄^2?. The resulting catalyst showed high activity and selectivity in the oxidation of sulfides to sulfoxides with H₂O₂ as a green oxidant at room temperature. In addition, due to the presence of ammonium groups in the catalyst structure, water dispersibility of the catalyst was increased. More important, the catalyst was magnetically recovered and reused for up to six runs without any marked decrease of activity and selectivity. Finally, easy gram‐scale oxidation of methylphenyl sulfide as well as fast separation of catalyst and product makes the protocol economical and industrially applicable.     

Chiral Bis(oxazoline)-copper Catalyzed Enantioselective Imidation of Sulfides

Prochiral sulfides reacted with Phl=NTs in the presence of a catalytic amount of Cu(I) salt together with a chiral 4,4′-disubstituted bis(oxazoline) ligand to afford the corresponding chiral sulfimides.     

Olefin Synthesis via,the Li-Derivative of N,N,N′,N′-Tetramethyldimides of Arylmethanephosphonic Acids

Abstract

The high erythro-stereoselective reaction of Li-tetramethyldiamides of arylmethanephosphonic acids with carbonyl compounds is used for synthesis of (Z)-alkenes by thermolysis of the erythro-adducts as well as in acidic media.     

Mechanochemical synthesis of PbS/Ni–Cr layered double hydroxide nanocomposite

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Membrane-based microchannel device for continuous quantitative extraction of dissolved free sulfide from water and from oil

Underground fluids are important natural sources of drinking water, geothermal energy, and oil-based fuels. To facilitate the surveying of such underground fluids, a novel microchannel extraction device was investigated for in-line continuous analysis and flow injection analysis of sulfide levels in water and in oil. Of the four designs investigated, the honeycomb-patterned microchannel extraction (HMCE) device was found to offer the most effective liquid–liquid extraction. In the HMCE device, a thin silicone membrane was sandwiched between two polydimethylsiloxane plates in which honeycomb-patterned microchannels had been fabricated. The identical patterns on the two plates were accurately aligned. The extracted sulfide was detected by quenching monitoring of fluorescein mercuric acetate (FMA). The sulfide extraction efficiencies from water and oil samples of the HMCE device and of three other designs (two annular and one rectangular channel) were examined theoretically and experimentally. The best performance was obtained with the HMCE device because of its thin sample layer (small diffusion distance) and large interface area. Quantitative extraction from both water and oil could be obtained using the HMCE device. The estimated limit of detection for continuous monitoring was 0.05 μM, and sulfide concentrations in the range of 0.15–10 μM could be determined when the acceptor was 5 μM FMA alkaline solution. The method was applied to natural water analysis using flow injection mode, and the data agreed with those obtained using headspace gas chromatography-flame photometric detection. The analysis of hydrogen sulfide levels in prepared oil samples was also performed. The proposed device is expected to be used for real time survey of oil wells and groundwater wells.     

A hidden rule in metal sulfide fullerenes: A case study of Sc2S@C88

To elucidate the structure of a compound is a necessary step for its practical applications. To study the structure and properties of metal sulfide fullerene Sc₂S@C₈₈ detected by mass spectrometry, 11 194 isomers of C₈₈ and 33 isomers of Sc₂S@C₈₈ were systematically examined by density functional theory calculations. The calculations show that the two lowest‐energy isomers are Sc₂S@C₈₈:81 738 (IPR‐35) and Sc₂S@C₈₈:81 735 (IPR‐32), followed by Sc₂S@C₈₈:81 729 (IPR‐26), Sc₂S@C_88:81 712 (IPR‐9), and Sc₂S@C_88:81 733 (IPR‐30). Structural analysis shows that the first two energetically favored isomers are bridged by the third and fifth energetically favored isomers, which can transfer into each other via direct Stone–Wales rotation. The calculations of temperature effect show that the first two favored isomers become dominant forms of Sc₂S@C₈₈ with decreasing temperature and may coexist in the soot. This structural convertibility among favored isomers of Sc₂S@C₈₈ suggest a hidden rule that birds of a feather flock together in metal sulfide fullerenes. This rule may decrease the range of candidate cages for the structural identification of a metal sulfide fullerene. IR spectra are simulated for helping the future experimental identification of Sc₂S@C₈₈.