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  • Ni 0.9 Mn 0.1 Fe 2 O 4 nanoparticles preparation and sunlight-utilized photocatalytic activity
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-11-02
    O. Raina, B. Prakash

    Abstract The metal hydrazine precursor of Ni0.9Mn0.1Fe2O4 nanoparticles was prepared through co-precipitation technique. Infrared spectrum of the precursor was showed the bridging bidentate nature of hydrazine. Multistep endothermic mass loss was observed from the thermogravimetric–differential thermogravimetric curves of the precursor. Ni0.9Mn0.1Fe2O4 nanoparticles synthesized from the precursor using thermal decomposition technique were characterized by infrared spectroscopy, energy-dispersive spectroscopy, powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry and UV-diffuse reflectance spectroscopy which proposed the phase structure, morphology, magnetic and optical properties. An effective photocatalytic activity has shown by Ni0.9Mn0.1Fe2O4 nanoparticles on Congo red, malachite green, methylene blue, methyl red, rhodamine B and rose bengal under direct sunlight at different time intervals. The nanoparticles were magnetically separated and showed good recycling ability.

    更新日期:2020-01-23
  • Sulfonated magnetic nanocatalyst and application for synthesis of novel Spiro[acridine-9,5′-thiazole]-1,4′-dione derivatives
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-10-14
    Hadi Mohammadi, Hamid Reza Shaterian

    Abstract Sulfonated Sulfurol supported Fe3O4 (Fe3O4@SiO2-Pr-Sulfurol-SO3H) a new magnetic reusable nanocatalyst was prepared using chemical modification of magnetic nanoparticles (MNPs) surface with Sulfurol-SO3H. The Sulfurol-SO3H moieties on the surface of MNPs act as acidic catalytic sites for catalysis purposes. Fe3O4@SiO2-Pr-Sulfurol-SO3H was authenticated by usual analytical and spectroscopic techniques. The prepared Fe3O4@SiO2-Pr-Sulfurol-SO3H MNPs were applied to the preparation of novel Spiro[acridine-9,5′-thiazole]-1,4′-dione derivatives via the three-component condensation of isatins, dimedone and thioamides or thioureas.

    更新日期:2020-01-23
  • Biosynthesis of TiO 2 nanoparticles and their superior antibacterial effect against human nosocomial bacterial pathogens
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-05-24
    S. Priyadarshini, Azizah Mainal, Faridah Sonsudin, Rosiyah Yahya, Abdullah A. Alyousef, Arshad Mohammed

    Abstract Antibacterial titanium dioxide nanoparticles (TiO2NPs) were biologically synthesized by microwave irradiation of Cissus quadrangularis extract followed by calcination at 450 °C for 3 h. As-synthesized nanoparticles were characterized by Fourier-transform infrared spectroscopy, X-ray diffraction analysis, and high-resolution transmission electron microscopy. The bioactivity of TiO2NPs against human nosocomial Gram-positive and Gram-negative bacterial pathogens (Staphylococcus aureus, Bacillus subtilis, and Escherichia coli) in liquid media was analyzed in the dark and under ultraviolet (UV, 365 nm) illumination. TiO2NPs demonstrated inhibitory effects against bacteria in dark, and enhanced bactericidal effect under UV illumination. Photoactivation generated holes (h+) and electrons (e−) on the surface of the TiO2NPs, inducing hydroxyl (OH−) and superoxide free radicals (.O2−) reactive oxygen species (ROS) on the bacterial surface. Furthermore, the interaction between the pathogenic bacteria and TiO2NPs was investigated by bacterial killing assay, colony counting, and viability assay using confocal microscopy. The experimental results revealed that the photoenhanced antibacterial effect of TiO2NPs makes them worth considering as a disinfectant for hospital garments.

    更新日期:2020-01-23
  • Preparation and photocatalytic properties of biomorphic hierarchical WO 3 based on bionic rice hull
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-11-21
    Yingzi Lin, Yang Zhu, Ang Li, Tianmo Wu, Yingji Song

    Abstract In this study, biomorphic WO3-Cx nanomaterial was successfully prepared with rice hull as biological templates. The structure and morphology of the nanomaterial showed that WO3-Cx efficiently copied the original pore-shaped appearance of the rice hull with a specific surface area of 199.18 m2/g. Results of UV–Vis diffuse reflectance spectroscopy and photoluminescence spectroscopy showed that the carbon element of the rice hull biological template promoted the light response range of WO3-Cx, inhibiting the hole–electron composite. The effects of biomorphic WO3-Cx and commercially available WO3 combined with sunlight on the photocatalytic degradation of methylene blue (MB) were studied. Results showed that the degradation rate of biomorphic WO3-Cx to MB solution was higher than that of commercially available WO3 for 44%. WO3-Cx with a concentration of 0.05 mol/L and dose of 0.5 g/L had remarkable degradation activity to MB (10 mg/L). In addition, the quasi-first-order kinetic model could well fit the degradation process with a dynamic constant of 0.0246 min−1.

    更新日期:2020-01-23
  • A simple synthesis of magnetic nanoparticles-supported 4-aminomethylbenzoic acid as a highly efficient and reusable catalyst for synthesis of 2-amino-4 H -chromene derivatives
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2017-06-23
    Mohammad Mehdi Khodaei, Abdolhamid Alizadeh, Maryam Haghipour

    Abstract A new 4-aminomethylbenzoic acid-functionalized Fe3O4 magnetic nanoparticles as a hybrid heterogeneous catalyst was synthesised and characterized by FT-IR, XRD, TGA, TEM, SEM and VSM techniques. The catalytic activity of this nanocatalyst was probed through one-pot synthesis of 2-amino-4H-chromene derivatives from three component reactions of various aldehydes, malononitrile and dimedone. The chemically and thermally stable catalyst was easily recovered using an external magnet and reused for at least five successive runs without significant loss of its activity. The simplicity of the method, high yields of the products, mild reaction conditions and low reaction times are the other advantages of this procedure.

    更新日期:2020-01-23
  • Preparation and electromagnetic wave absorption properties of polymer nanocomposites based on new functionalized graphene oxide iron pentacarbonyl and ionic liquid
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-11-27
    Azam Abedini Pozveh, Elaheh Kowsari, Mohammad Mahmoudi Hashemi, Zohreh Mirjafari

    Abstract This paper presents the preparation of a new epoxy nanocomposite of functionalized graphene oxide (FGO) and iron pentacarbonyl [Fe(CO)5] (IPC) as electromagnetic (EM) absorber. In this EM absorption (EMA) compound, FGO has been used to increase the electrical absorption, while by adding IPC, its magnetic absorption capacity has been improved. Graphene oxide (GO) was functionalized in three steps with imidazole (C3H4N2) and 3-bromo-1-phenyl-1-propene (3-phenylallyl bromide). The resultant FGO was of an ionic liquid structure, and it was determined using Raman spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and field emission scanning electron microscopy. FGO–IPC/epoxy resin nanocomposite (FIERC) was produced using 10–40 wt.% with variable thickness as an EM absorber material. The FIERC with 30 wt.% and 2 mm thickness showed great EMA in the X-band frequency (8–12 GHz), and the minimum reflection loss (RL) is displayed in 9–10 GHz (− 80 dB).

    更新日期:2020-01-23
  • An efficient method for the synthesis of new derivatives of 2,4,6-triarylpyridines as cytotoxic agents
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-10-26
    Bahram Ahmadi Baloutaki, Mohammad Hosein Sayahi, Mohammad Nikpassand, Hassan Kefayati

    Abstract New series of 2,4,6-triarylpyridines derivatives 5a–f and 6a–d were designed, synthesized and evaluated for their cytotoxic activity against breast cancer cell lines. Three-component reaction between acetophenones, ammonium acetate and 4-methyl or 2-methylpyridine in the presence of iodine in DMSO lead to title 2,4,6-triarylpyridines. This method allows the simple preparation of the desired products using readily available reagents under mild reaction conditions in good yields. Synthesized compounds were investigated for their cytotoxic activities against MDA-MB-231, MCF-7 and T-47D cell lines. Most of the synthesized compounds showed remarkable cytotoxicity, comparable to standard drug etoposide.

    更新日期:2020-01-23
  • Nitrogen-doped carbon enhanced mesoporous TiO 2 in photocatalytic remediation of organic pollutants
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2018-07-20
    Dian Li, Yupu Liu, Hong Liu, Zhihua Li, Li Lu, Jun Liang, Zhonghui Huang, Wei Li

    Abstract Controllable synthesis of mesoporous photocatalysts is of great interest for the photocatalytic remediation of organic pollutants from wastewater by sunlight. In this work, we have developed a new photocatalyst with nitrogen-doped carbon (NC) and mesoporous TiO2 (mTiO2) interpenetrating hetero-structure by a sol–gel process combined with an in situ carbonization strategy. The synthesized nanospheres possess a uniform particle size (~ 60 nm), high surface area (~ 108 m2/g), and large pore diameter (~ 2.1 nm). Most importantly, the nanospheres consist of ultrasmall TiO2 nanocrystals (~ 8.2 nm), which are uniformly coated by a thin layer of N-doped carbon. Significantly, the resultant NC/mTiO2 composite nanospheres exhibit a broad light absorption in the range of 200–2000 nm (entire wavelength). When serving as a photocatalyst for organic pollutants degradation, high performance was obtained. Accordingly, the resultant NC/mTiO2 composite nanospheres performed in an excellent manner in the photodegradation of methyl orange, and the total removal efficiency was up to 97.7%, much better than that of commercial P25 (19.8%). Furthermore, the nanocomposite also effectively photodegraded other organic pollutants such as methylene blue (dyestuff) and phenol, respectively. Therefore, the resultant NC/mTiO2 nanocomposites have potential applications in environmental cleanup.

    更新日期:2020-01-23
  • One-pot synthesis of 2-amino-3-cyanopyridines and hexahydroquinolines using eggshell-based nano-magnetic solid acid catalyst via anomeric-based oxidation
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-11-30
    Tahere Akbarpoor, Ardeshir Khazaei, Jaber Yousefi Seyf, Negin Sarmasti, Maryam Mahmoudiani Gilan

    Abstract In the present research, the eggshell as a hazardous waste by European Union regulations was converted to a valuable catalyst, namely nano-Fe3O4@(HSO4)2. The as-prepared catalyst, first, was characterized using different techniques, including Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). Back-titration method confirmed the loading of a high surface density of acidic group, namely 8.8 mmol HSO4 per gram of the catalyst. The catalytic property of the as-prepared catalyst was examined in the synthesis of 2-amino-3-cyanopyridines via anomeric-based oxidation (ABO), and hexahydroquinolines derivatives. High yield, short reaction time, solvent-free condition, waste to wealth, and optimization with the design of experiment are the major advantages of the present work. Taken together, these results suggest the conversion of waste to wealth products around the world and usage in organic transformation. Graphic abstract

    更新日期:2020-01-23
  • Highly efficient photodegradation of 4-nitrophenol over the nano-TiO 2 obtained from chemical bath deposition technique
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-10-28
    S. V. Kite, D. J. Sathe, A. N. Kadam, S. S. Chavan, K. M. Garadkar

    Abstract Herein, we report the collection of TiO2 nanopowder after successful thin film deposition. The obtained TiO2 nanopowder was utilized for photodegradation of 4-nitrophenol (4-NP). The structural, optical, morphological, thermal and photocatalytic properties of TiO2 photocatalyst were systematically studied using XRD, Raman, HR-TEM, FT-IR, FE-SEM, EDS, UV–Vis, DRS, PL, BET and TGA. From XRD, we correlate crystallinity parameters like crystallite domain size, lattice cell parameters, unit cell volume, microstrain, stacking fault and dislocation density. TiO2 nanopowder annealed at 400 °C shows the anatase phase which is confirmed by Raman and XRD analyses. In addition, optical results indicate that the absorption band edge is positioned in the UV region with bandgap energy of 3.03 eV. The FE-SEM and TEM images of TiO2 nanopowder show irregular spherical morphology which results in the aggregation of nanoparticles with a mean diameter of 27 nm. From Brunauer–Emmett–Teller (BET) adsorption isotherm, the surface area was obtained to be 38 m2/g. The TGA curve demonstrates the thermodynamically stable anatase phase of TiO2 photocatalyst appeared in the 350–750 °C. Under UV light irradiation, photodegradation of 4-NP over 1.5 g/dm3 TiO2 photocatalyst dose achieved an excellent degradation efficiency and COD removal efficiency around 99.51 and 82% within 80 min, respectively. From trapping experiments, it indicates that OH· and O2· radicals are major reactive oxygen species involved in the photodegradation of 4-NP.

    更新日期:2020-01-23
  • Photocatalytic UV degradation of 2,3,7,8-tetrachlorodibenzofuran in the presence of silver zeolite
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2017-02-24
    Fatin Samara, Maitha Al Shamsi, Faisal Kanaan, Sofian M. Kanan

    Abstract Silver clusters were introduced into the framework of zeolite Y. Low-temperature solid-state luminescence indicates the formation of silver–silver excimers and exciplexes that were found to be activated at 250 and 300 nm, respectively. The photodegradation of a persistent halogenated organic pollutant, namely 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF), was studied in the presence and absence of two catalysts, namely including AgY1 and AgY2, under mid- and high energy: 302 and 254 nm, respectively. The results showed that in the absence of a catalyst, degradation under 254-nm UV light resulted in changes to the peak intensity as well as energy, while the 302-nm profile showed only loss in peak intensity. In the presence of either catalyst, a higher rate of degradation of the 2,3,7,8-TCDF was observed. The amount of the adsorbed 2,3,7,8-TCDF on the AgY1 and AgY2 catalyst was estimated to reach 37.9 and 18.9% of its initial concentration, respectively. The toxicity of the intermediate and resultant products was further analyzed with the aid of an enzyme-linked immunosorbent assay. The optical density showed that in contrast to all the samples, the TCDF irradiated with 254 nm in the presence of AgY2 was high at 40 min inferring a decrease in toxicity of the resultant product. The present work shows an innovative and cost-efficient technique for the removal of dioxins and furans from water sources.

    更新日期:2020-01-23
  • Toward the synthesis of thiadiazole-based therapeutic agents: synthesis, spectroscopic study, X-ray analysis, and cross-coupling reactions of the key intermediate 3,5-diiodo-1,2,4-thiadiazole
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-11-30
    Mohammed Boulhaoua, Ana Torvisco, Tibor Pasinszki

    Abstract The 1,2,4-thiadiazole moiety is an important component of several biologically active compounds, and varying substituents on this aromatic ring is one of the possible methods to develop novel thiadiazole-based drugs for medicine. A key building block to this end, namely 3,5-diiodo-1,2,4-thiadiazole (1), has been synthesized and characterized in this work for the first time. 1 has exhibited high selectivity for the replacement of iodine atom at position C5 (carbon next to sulfur) in Sonogashira-type cross-coupling reactions with phenylacetylene. Therefore, 3-iodo-5-(phenylethynyl)-1,2,4-thiadiazole (4) or 3,5-bis(phenylethynyl)-1,2,4-thiadiazole (5) could be synthesized selectively depending on reaction conditions. All three novel molecules have been characterized by NMR, IR, Raman, mass, and UV spectroscopies, and their solid phase structures have been determined by single-crystal X-ray diffraction. 1 is expected to be a key starting material for producing thiadiazole-based therapeutic agents using cross-coupling reactions.

    更新日期:2020-01-23
  • A robust and recyclable ionic liquid-supported copper(II) catalyst for the synthesis of 5-substituted-1 H -tetrazoles using microwave irradiation
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-11-02
    R. D. Padmaja, Kaushik Chanda

    Abstract A novel and robust ionic liquid-supported copper(II) catalyst has been developed and explored for the efficient synthesis of 5-substituted-1H-tetrazoles using microwave irradiation. The ionic liquid-supported catalyst facilitated the efficient isolation of tetrazole products with high purity by simple extraction with organic solvent. Recovered ionic liquid-supported copper(II) catalyst could be recycled for three times for the synthesis of tetrazole products with high purity. This synthetic protocol offers a very clean, convenient, and microwave-assisted environment-friendly method for the efficient synthesis of 5-substituted-1H-tetrazoles with high yield. Graphic abstract

    更新日期:2020-01-23
  • Facile synthesis and kinetic mechanism of Ag-doped TiO 2 /SiO 2 nanoparticles for phenol degradation under visible light irradiation
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-10-29
    Miaomiao Fan, Guodong Fan, Guoxian Zhang, Shaofang Zheng

    Abstract Ternary Ag–TiO2–SiO2 nanocomposite photocatalysts were synthesized via a facile sol–gel method and characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscope, X-ray photoelectron spectroscopy, surface area analyzer (BET method) and UV-diffuse reflectance spectroscope, respectively. The results indicated that the crystallite size of TiO2 reduced after being doped by SiO2 and Ag, while the agglomeration and phase transition of TiO2 nanoparticles were restrained, resulting in the greatly increased specific surface area of Ag–TiO2–SiO2. Moreover, the adsorption edge of TiO2 obviously red-shifted from UV to visible light range, indicating the higher utilization of solar energy. The photocatalytic performance was evaluated by the degradation of phenol under visible light (λ > 420 nm) irradiation. The degradation rate of phenol over 1%Ag–TiO2–SiO2 reached 91.1% after illumination for 180 min, which was significantly higher than that of TiO2. This work provided a simple method to prepare highly active TiO2-based photocatalysts.

    更新日期:2020-01-23
  • Synthesis of a novel hyperbranched polymer and its application in multi-channel sensing Fe 3+
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-11-13
    Tengxuan Tang, Jing Wang, Dongmei Xu

    Abstract A novel hyperbranched polymer was designed and synthesized as a spectral probe for Fe3+. The polymer showed high selectivity and sensitivity to Fe3+ in CH3CN/H2O (75/25, v/v). Fe3+ caused a new peak at 560 nm in UV–Vis absorption, a 31 nm fluorescence redshift, a 35-fold enhancement in fluorescence intensity at 575 nm and an 8.3-fold enhancement in fluorescence quantum yield, accompanied by a visual color change from colorless to pink and a fluorescence from dark to bright orange. The colorimetric and fluorescent detection limits were 1.29 and 1.88 µM, respectively. The detection was almost not interfered by other common metal cations. The polymer could be applied in assaying Fe3+ in real sample with similar precision to that of atomic absorption spectroscopy.

    更新日期:2020-01-23
  • Synthesis of reduced graphene oxide functionalized with methyl red dye and its role in enhancing photoactivity in TiO 2 –IL/WO 3 composite for toluene degradation
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-10-22
    Elaheh Kowsari, Fariba Morad, Naemeh Seifvand, Behrouz Bazri, Maryam Karimi

    Abstract A nanostructured composite material was produced through sol–gel-assisted ionic liquid (IL) synthesized TiO2, WO3 and functionalized reduced graphene oxide (FRGO), respectively. IL was selected and used as shape and size controller in TiO2 synthesis as well. GO nanosheets were functionalized with (E)-2-[4-(dimethylamino) phenyl] benzoic acid (methyl red dye) in order to absorb more light. The products were characterized using X-ray diffraction spectroscopy, scanning electron microscopy, transmission electron microscopy, N2 adsorption–desorption methods, FTIR, Raman, photoluminescence and X-ray photoelectron spectroscopy. The photocatalytic activity of TiO2–IL/WO3/FRGO composite in toluene degradation under visible-light irradiation was evaluated by gas chromatography. The prepared composite demonstrated significant toluene degradation (ca. 74%) after only 2 min of reaction in comparison to TiO2–IL/WO3 composite (51%), TiO2–IL (40%) and pure TiO2 (17%). These results are due to the combination of FRGO and WO3 with TiO2 by their properties like stability, high surface area and low band gap.

    更新日期:2020-01-23
  • MCM-41@Schiff base-Co(OAc) 2 as an efficient catalyst for the synthesis of pyran derivatives
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-11-14
    Shiwei Pan, Puhui Li, Guihua Xu, Jingchang Guo, Libin Ke, Canquan Xie, Zhoucai Zhang, Yonghai Hui

    Abstract Heterogeneous ordered mesoporous silica materials catalyst, MCM-41@Schiff base-Co(AcO)2, reveals high catalytic performance within the synthesis of pyran derivatives using the multicomponent reaction of aldehydes, malononitrile and 2-naphthol (or cyclohexane-1,3-dione) in water. The reactions afforded the desired products in high yields (up to 97% and 95%). The substantial feature is that the mesoporous-complex catalyst could be easily separated from the reaction mixture by centrifugation and reused at least 6 times with more than 80% yield in activity. The gram-scale experiments were achieved with good yields and implied that the catalytic method was effective and convenient for heterocyclic synthesis. What is more, the synthesized catalyst was characterized using various spectroscopic techniques to obtain the structural and functional features. The analysis results confirmed that the Co-Schiff base complex immobilized on the surface of mesoporous materials MCM-41. Finally, a plausible reaction mechanism was proposed.

    更新日期:2020-01-23
  • Microwave-assisted hydrothermal synthesis of BiOBr/BiOCl flowerlike composites used for photocatalysis
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-21
    Wachiraporn Maisang, Surin Promnopas, Sulawan Kaowphong, Suparut Narksitipan, Somchai Thongtem, Surangkana Wannapop, Anukorn Phuruangrat, Titipun Thongtem

    Abstract BiOBr/BiOCl flowerlike composites were successfully synthesized in different solutions containing 0.00–1.50 g polyvinylpyrrolidone (PVP) by microwave-assisted hydrothermal method. The as-synthesized BiOBr/BiOCl composites were studied by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, UV–visible diffuse reflection spectroscopy, photoluminescence spectroscopy, electrochemical impedance spectroscopy and photocatalysis. In this research, the morphologies of tetragonal BiOBr and tetragonal BiOCl products were transformed from BiOBr/BiOCl microplates without PVP into BiOBr/BiOCl microflowers with 1.00 g added PVP. The BiOBr/BiOCl microflowers have optimal visible light absorption and demonstrate excellent photocatalytic activity in degradation of rhodamine B and salicylic acid under xenon radiation. These composites are promising materials used for wastewater treatment.

    更新日期:2020-01-22
  • Synthesis and characterization of functionalized NaP Zeolite@CoFe 2 O 4 hybrid materials: a micro–meso-structure catalyst for aldol condensation
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-21
    Zohreh Mortezaei, Mojgan Zendehdel, Mohammad Ali Bodaghifard

    Abstract In this work, magnetic nanocomposite of NaP Zeolite and CoFe2O4 as magnetic nanoparticles (MNP’s) with different ratios were prepared and in the second step functionalized with 2-aminopyridine as a basic group. All samples were characterized by FT-IR, XRD, VSM, FESEM, EDX, TEM, and BET and thermal analyses. The results show that CoFe2O4 MNP’s was dispersed on NaP Zeolite without any significant aggregation with particle size about 30–50 nm. The BET and TEM confirmed the presence of mesoporous phase in the surface of NaP Zeolite/CoFe2O4 and preparation a micro–meso-structure. The NaP Zeolite/CoFe2O4 and NaP Zeolite/CoFe2O4/Am-Py were used as acid–base catalysts for aldol condensation of cyclohexanone with benzaldehyde, and furfural with acetone which produce curcumin and biofuel intermediates, respectively, in solvent-free condition. The effect of different factors such as the percent of CoFe2O4 MNP’s, catalyst amount, solvent, time and temperature was investigated. The catalyst was easily separated with an external magnet and reused four times without significant change in the yield. These catalysts have various advantages including high loading capacity, low leaching for CoFe2O4 MNP’s and simple and efficient recovery procedure which can be used under mild and ecofriendly condition.

    更新日期:2020-01-22
  • Hyper-cross-linked β-cyclodextrin nanosponge: a three-dimensional, porous and biodegradable catalyst in the one-pot synthesis of kojic acid-based heterocyclic compounds
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-21
    Rezvan Kardooni, Ali Reza Kiasat, Nima Eskandari Sabzi

    Abstract In the present study, β-cyclodextrin-based nanosponges were prepared by reaction of β-cyclodextrin with dicarbonyl imidazole as a crosslinker agent. The synthesized polycarbonate nanosponge was characterized by FT-IR spectroscopy, thermogravimetric analysis, scanning electron microscopy and Brunauer–Emmett–Teller. The catalytic activity of β-cyclodextrin-based nanosponges was successfully tested in the one-pot three-component condensation of kojic acid, aromatic aldehydes and various aromatic amines. The superiority of this new strategy is short reaction times, high yields and utilizing of biodegradable and nontoxic nanocatalyst.

    更新日期:2020-01-22
  • Exploring removal of formaldehyde at room temperature over Cr- and Zn-modified Co 3 O 4 catalyst prepared by hydrothermal method
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-20
    Junliang Xie, Mianwu Meng, Zhihao Lin, Hua Ding, Jianhua Chen, Siyu Huang, Zhenming Zhou

    Abstract The metal-modified Co3O4 sample (metal: Zn or Cr, Zn and Cr) was prepared through hydrothermal approach, and applied in low concentration of HCHO removal under room temperature. The Cr/Zn/Co3O4 exhibited the best formaldehyde removal activity and stability. The effect of dopants on the physicochemical properties of the Co3O4 samples was characterized by X-ray diffraction, Raman, N2 adsorption–desorption, scanning electron microscopy, transmission electron microscopy, thermogravimetric (TG-DTG) and X-ray photoelectron spectroscopy, resulting that the Cr/Zn/Co3O4 sample possessed the optimal specific surface area (177.53 m2/g, 3.4 times that of pure Co3O4). Meanwhile, Cr and Zn incorporated into Co3O4 lattice simultaneously and promoted the formation of defects, which is the prerequisite for increasing the reactive oxygen species of Cr/Zn/Co3O4. In addition, Cr6+/Cr3+ ion pairs in the sample could be an important role in the removal of formaldehyde. It is concluded that the ideal HCHO removal performance and stability of Cr/Zn/Co3O4 were associated with its high vacancy oxygen content, excellent specific surface area and the promotion of Cr6+/Cr3+ ion pairs. Graphic abstract

    更新日期:2020-01-21
  • A reusable reduced graphene oxide-cobalt oxide nanocomposite with excellent yield as adsorbent for determination trace-level of brilliant green in environmental water samples
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-14
    Rouhollah Khani, Majid Irani

    Abstract In view of large-scale production, usage and toxic nature, the synthetic dyes are a very significant category of pollutants. This work reports the preparation and application of reduced graphene oxide/cobalt oxide (rGO/Co3O4) nanocomposite as selective and regenerable magnetite nanosorbent for the preconcentration and determination of brilliant green (BG) as a synthetic dye by UV–Vis spectrophotometry. The properties of the rGO/Co3O4 nanocomposite were characterized by UV–Vis spectrophotometry, Fourier-transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, vibrating sample magnetometer and inductively coupled plasma optical emission spectrometry. Magnetic dispersive microsolid phase extraction (MD-μSPE) as a green, simple and sensitive method has been proposed for the separation and determination of trace quantities of BG. The experimental parameters affecting the MD-μSPE efficiency for the target analytes such as sample pH, brilliant green concentration, adsorbent dose and sonication time were investigated and optimized by central composite design coupled with desirability function approach. Under the optimized conditions, the detection limit, relative standard deviation and enrichment factor were 2.6 ng mL−1, 3.34% (n = 5) and 24.5, respectively. Finally, the applicability of the proposed method was successfully evaluated by the determination of trace amounts of BG in fish breeding pool and tap water samples.

    更新日期:2020-01-14
  • Promoting effect of multi-transition metals on the NO reduction by NH 3 over TiO 2 catalyst studied with in situ DRIFTS
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-13
    Xincheng Wang, Xiangjun Zhang, Minyao He, Yongji Song, Cuiqing Li, Hong Wang

    NOx is one of the most detrimental pollutants to the atmospheric and ecological environment. Currently, selective catalytic reduction (SCR) of NOx by NH3 was conducted by transition metals-doped (Mo, Ce, Cu, Fe, W, and Zr, including P) TiO2 catalysts through orthogonal experimental design. It was found that Mo, Cu, Fe, and Zr significantly affected the catalytic activity, while Mo showed the highest impact. The optimum amounts of Mo, Ce, Cu, Fe, W, P, and Zr were 1.5 wt%, 2 wt%, 6 wt%, 4 wt%, 0 wt%, 0.9 wt%, and 4 wt%, respectively. The catalysts’ redox properties and adsorption capacity for NO were key factors affecting the catalytic activity. Proper amounts of adsorbed oxygen, together with appropriate adsorption capacity for NO and acidity distribution, were beneficial for the formation of intermediates. The mechanistic cause of the promoting effect of metal oxides for NH3-SCR was studied using in situ DRIFTS. These results revealed that the addition of metal oxides is to promote the adsorption and activation of NH3 on the catalyst surface, which is beneficial for the promotion of SCR activity.

    更新日期:2020-01-14
  • Improved catalytic properties of Co 3 O 4 -impregnated La 2 O 3 /MgO over Co 3 O 4 /MgO catalyst in the oxidative dehydrogenation of ethylbenzene
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-13
    Venkata Rao Madduluri, Raju Narsinga, Dosa Mallesh, P. Mahesh Kumar, Shankar Barapati, Sreedhar Bojja, Kamaraju Seetha Rama Rao

    Abstract A series of lanthanum oxide (La2O3—2–14 wt%)-encapsulated Co3O4/MgO catalysts and bare Co/MgO solid oxides were prepared by wetness impregnation method. Among all catalysts, La2O3-promoted Co3O4/MgO (CM) was found to be remarkable in terms of superior promotional effect of La oxide species. Therefore, La2O3-incorporated Co3O4/MgO (LCM) catalysts afforded unusual catalytic activity efficiency with respect to high EB conversion and styrene selectivity due to the synergistic effect of Co–La species. By contrast, bare Co3O4/MgO solid oxide (CM) catalyst afforded low EB conversion with mild catalytic activity due to the absence of promotional role of La oxide.

    更新日期:2020-01-13
  • Imin-based synthesis of polyfunctionalized dihydro-2-oxypyrroles catalyzed by glycine amino acid via tandem Michael–Mannich cyclocondensation reaction under ambient temperature
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-11
    Farzaneh Mohamadpour

    An efficient and mild synthetic route to the convenient one-pot preparation of polyfunctionalized dihydro-2-oxypyrroles has been developed and catalyzed via glycine amino acid as a natural bio-based and biodegradable catalyst using imin-based four condensation domino reaction of amines, dialkyl acetylenedicarboxylates and formaldehyde via tandem Michael–Mannich cyclocondensation reaction under ambient temperature. The reactions complete in less time, but the products are obtained in outstanding yields. This environmentally friendly method includes the noticeable properties such as bio-based and green catalyst, direct workup without column chromatographic separation, cost-effective, mild and simple synthesis, one-pot procedure and high atom economy.

    更新日期:2020-01-13
  • Synthesis of new polyaryl-substituted imidazoles bridged on enamine or urea moieties and evaluation of their optical and electrochemical properties
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-11
    Ameneh Abolghassemi Fakhree, Roghayeh Mohammadzadeh, Esmaeel Alipour, Zarrin Ghasemi

    Abstract The reaction of the free amine group in polyaryl-substituted imidazole structures with phenyl isocyanate or dimethyl acetylenedicarboxylate gave two new series of polyaryl-substituted imidazoles: biaryl ureas or vinyl esters, respectively. Besides their spectroscopic analysis, we explored the optical and electrochemical properties of these highly conjugated scaffolds. Comparing these properties in two categories of products yielded interesting results. Graphic abstract

    更新日期:2020-01-13
  • Structures and electronic and magnetic properties of the 3 d transition metal-substituted TMC 5 N 8 clusters
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-11
    Zhi Li, Zhen Zhao, Zhong-suo Liu, Hong-bin Wang, Qi Wang

    The structures and electronic and spin properties of the 3d TMC5N8 clusters have been calculated using the PBE functional. The results demonstrate that the Zn atom substituting significantly distorts the C6N8 clusters. TM atoms prefer to substitute the C atom which is farthest away from the biasing N atom. The TM substituting dramatically reduces the structural stability of the C6N8 clusters except for ScC5N8, TiC5N8 and VC5N8. As for the ground-state TMC5N8 clusters, the TM substituting improves the kinetic stability of the C6N8 clusters except for Ti, Cr and Cu. TM atoms in the TMC5N8 clusters loss certain amount of electrons. A few 4s orbital electrons of TM atoms transferred to the N atoms in the TMC5N8 clusters. The maximum spin values of the TM atoms occur at Mn and Ni for the TMC5N8 clusters.

    更新日期:2020-01-13
  • Rapid and green synthesis of 4H-benzo[b]pyrans using triethanolamine as an efficient homogeneous catalyst under ambient conditions
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-10
    Reyhaneh Rahnamafa, Leila Moradi, Mehdi Khoobi

    Abstract 4H-benzo[b]pyrans were obtained rapidly in high yields using triethanolamine as an efficient, eco-friendly and low-cost basic catalyst. One-pot three-component condensation reaction of a series of aldehydes, malononitrile and 1,3-diketones was performed at room temperature. All the products were obtained in high-to-excellent yields and characterized in detail. Green, rapid and mild process, very short reaction times (1–12 min) and simple workup are some of the advantages of this method.

    更新日期:2020-01-11
  • Design, synthesis and exploration of in silico α-amylase and α-glucosidase binding studies of pyrrolidine-appended quinoline-constrained compounds
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-09
    P. Hemanth Kumar, L. Jyothish Kumar, G. Pavithrra, R. Rajasekaran, V. Vijayakumar, Rohith Karan, S. Sarveswari

    Abstract A series of new pyrrolidine-appended phenoxy-substituted quinoline derivatives were synthesized using 2-chloro-3-formyl quinoline. Initially, the second position of 2-chloro-3-formyl quinoline was successfully converted into various substituted phenoxy-substituted quinolines using various substituted phenols; then, its aldehyde function was reduced to its corresponding alcohols which is in turn converted into its corresponding pyrrolidine-appended phenoxy-substituted quinolines by treating it with 1-(2-chloroacetyl)pyrrolidine-2-carbonitrile. All these newly synthesized compounds were subjected to the in silico studies with the α-amylase and α-glucosidase enzymes to predict the binding affinity.

    更新日期:2020-01-11
  • Retraction Note to: Optical properties of rare earth-doped barium aluminate synthesized by different methods-a review
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-08-17
    Jagjeet Kaur, Beena Jaykumar, Vikas Dubey, Ravi Shrivastava, N. S. Suryanarayana

    The Editor-in-Chief has retracted this article [1] because it contains material that substantially overlaps with the following articles (amongst others) [2–5].

    更新日期:2020-01-09
  • Correction to: One-pot synthesis of pyran derivatives using silica-coated magnetic nanoparticles functionalized with piperidinium benzene-1,3-disulfonate as a new efficient reusable catalyst
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-03-06
    Ramin Ghorbani-Vaghei, Vida Izadkhah, Jafar Mahmoodi

    In the original publication of the article, the graphical abstract was incorrectly published. The correct graphical abstract should be as given below.

    更新日期:2020-01-09
  • Synthesis, spectroscopic properties, crystal structures, antioxidant activities and enzyme inhibition determination of Co(II) and Fe(II) complexes of Schiff base
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-08-12
    Kenan Buldurun, Nevin Turan, Ercan Bursal, Asim Mantarcı, Fikret Turkan, Parham Taslimi, İlhami Gülçin

    Considering the importance of metal complexes in the development of medical science, two different Schiff base Fe(II) and Co(II) metal complex compounds were synthesized with Schiff base obtained through the condensation of 1-(4-aminophenyl)ethanone with 2-hydroxy-3-methoxybenzaldehyde. The reactions of the ligand with Co(II) and Fe(II) metal ions enabled six coordination compounds with octahedral geometries. The novel metal complexes were characterized by IR, elemental analyses, magnetic susceptibility, mass spectra, UV–Vis, thermogravimetry–differential thermal analysis (TGA–DTA) and X-ray diffraction analysis. The antioxidant properties of the new compounds were investigated using different in vitro assays. Moreover, enzyme inhibition of derivatives complexes against carbonic anhydrase I and II isoenzymes (CA I and II) and acetylcholinesterase (AChE) was evaluated. The best inhibitor complex for CA I and II isoenzymes was the Fe(II) complex with Ki values of 52.83 ± 11.52 and 63.34 ± 8.88, respectively.

    更新日期:2020-01-09
  • MCM-41-supported Fe(Mn)/Cu bimetallic heterogeneous catalysis for enhanced and recyclable photo-Fenton degradation of methylene blue
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-09-07
    Tao Sun, Mingfu Gong, Yuanqing Cai, Shilin Xiao, Liang Zhang, Ya Zhang, Zhongsheng Xu, Dong Zhang, Yun Liu, Chunyu Zhou

    Highly efficient bimetallic heterogeneous photo-Fenton catalysts (Fe2O3/CuO@MCM-41, FCM and MnOx/CuO@MCM-41, MCM) have been successfully prepared via wet impregnation over a mesoporous MCM-41 silica support. FESEM images demonstrate that the metal oxides are highly dispersed on the surface of the MCM-41 matrix consisting of the ordered 2D hexagonal mesostructure. XPS results indicate that the bimetallic oxides species in FCM and MCM are Fe2O3, CuO and MnOx, CuO, respectively. The as-prepared dual-heterojunctions have a significant enhancement of catalytic activities under visible light, compared with the material containing monometal, and prevents the leaching of metal ions species. The degradation efficiencies of MB can be up to 99.65% and 98.22% within 45 min irradiation for FCM1:2 and MCM1:0.5, respectively. And the degradation efficiencies still can reach up to 92% after 10 cycles. Moreover, the synthesized bimetallic dual-heterojunctions catalysts can be employed in very mild condition, and little difference in catalytic effect was observed under different pH value (3.0–9.0). The improved photocatalytic activity can be ascribed to the sufficient interfacial contact between different components for photo energy transfer and e−/h+ pairs separation, which greatly enhance cycle reaction of Fe3+/Fe2+ or Mn4+/Mn3+/Mn2+ after introducing CuO. This research provides a new approach for the development of an effective heterogeneous photo-induced Fenton (Fenton like) catalyst with vast potential for organic pollutant removal.

    更新日期:2020-01-09
  • Ternary system from mesoporous CdS–ZnS modified with polyaniline for removal of cationic and anionic dyes
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-09-12
    Heba Ali

    Abstract In this work, mesoporous CdS (130.7 m2/g) was prepared; then, ZnS was deposited by chemical bath deposition (CBD) and successive ionic layer adsorption and reaction (SILAR) method, to get CdS–ZnS(C) and CdS–ZnS(S), respectively. Subsequently, the highest efficient binary hybrid was sensitized with polyaniline to produce CdS–ZnS–PANI for the first time. XRD and EDX analyses confirmed the coating of CdS with ZnS using CBD and SILAR method. The careful examination for the surface morphology of the binary hybrids illustrated that CdS–ZnS(S) has uniform morphology and the CdS nanoparticles are homogeneously overcoated with ZnS. In contrast, CdS–ZnS(C) exhibits inhomogeneous surface, where there are ZnS particles that aggregate together and there is another region which contains ZnS deposited onto CdS. The estimated band gap of CdS, CdS–ZnS(S), and CdS–ZnS–PANI was 2.36 eV, 2.44 eV, and 1.9 eV, respectively. The removal efficiency for cationic and anionic dyes single and/or in combination using CdS, ZnS, CdS–ZnS(C), CdS–ZnS(S), PANI, and CdS–ZnS–PANI was studied. The effect of the amount of ZnS loaded by SILAR process on the activity of the CdS–ZnS(S) was presented. The results proposed that CdS–ZnS(S) exhibits selective adsorption and high removal efficiency for cationic dye compared to CdS–ZnS(C) due to higher negative zeta potential and large surface area. The CdS–ZnS–PANI ternary nanocomposite showed uptake efficiency of 96.7% for cationic dye (MB) and 94.3% for anionic dye (MO) in a mixed dye solution after 10 min. Finally, the possible adsorption mechanism was proposed. Graphic abstract

    更新日期:2020-01-09
  • Magnetic phosphonium ionic liquid: Application as a novel dual role acidic catalyst for synthesis of 2′-aminobenzothiazolomethylnaphthols and amidoalkyl naphthols
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-10-19
    Morteza Torabi, Meysam Yarie, Mohammad Ali Zolfigol, Saeid Azizian

    Abstract In this investigation, a novel magnetic phosphonium ionic liquid (MPIL) was designed and synthesized through a two-step process. The resulting magnetic ionic liquid was fully characterized using different techniques including Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), derivative thermogravimetric analysis (DTG), energy-dispersive X-ray spectroscopy (EDX) and vibrating sample magnetometer (VSM). The prepared dual acidic MPIL represents brilliant catalytic performance towards the synthesis of 2′-aminobenzothiazolomethylnaphthol and amidoalkyl naphthol derivatives. Combination of magnetic, Bronsted and Lewis acid ability within a single compound is the major advantage of prepared MPIL. The present work can open up a new and promising insight in the course of rational design, synthesis and applications of task-specific multi-rule magnetic ionic liquids for various purposes. Graphic abstract A novel magnetic phosphonium ionic liquid promoted the synthesis of 2′-aminobenzothiazolomethylnaphthols and amidoalkyl naphthol derivatives.

    更新日期:2020-01-09
  • Immobilization of horseradish peroxidase on polyglycerol-functionalized magnetic Fe 3 O 4 /nanodiamond nanocomposites and its application in phenol biodegradation
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-07-31
    Anxia Li, Xiaoxin Yang, Binglong Yu, Xiulan Cai

    Abstract In this study, Fe3O4/nanodiamond nanocomposites (MND) were synthesized by polyglycerol-mediated covalent bonding. The horseradish peroxidase (HRP) was successfully immobilized on PG layer of MND by interaction between functional groups of MND and HRP, where the HRP molecules became tridimensionally connected outside the MND. The physicochemical properties of MND were analyzed by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy measurements, vibrating sample magnetometer, Fourier transform infrared spectroscopy and zeta potential. The optimal conditions for the immobilization of HRP by MND are 7 mg/L, 35 °C and 3 h, respectively. Then, the effects of temperature, pH and storage time on the activity of immobilized enzyme and free enzyme were studied. The results showed that the relative activities of immobilized enzymes were higher than free enzymes at different temperatures, pH and storage time. In addition, the reusability experiments of immobilized enzymes showed that after six cycles, the immobilized HRP retained a relative activity of 75%. Applied to the removal of phenol, the effects of phenol concentration, H2O2/phenol molar concentration, immobilized HRP concentration and temperature on phenol removal were investigated. The results displayed that the removal efficiency of phenol reached a maximum when the phenol concentration was 75 mg/L, the ratio of H2O2 to phenol was 1, the immobilized HRP concentration was 0.25 mg/L and the temperature was 30 °C. The above results indicate that the immobilized HRP exhibits high removal efficiency and has great potential for removing phenol.

    更新日期:2020-01-09
  • Magnetic biochar derived from sewage sludge of concentrated natural rubber latex (CNRL) for the removal of Al 3+ and Cu 2+ ions from wastewater
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-08-29
    Khamphe Phoungthong, Thitipone Suwunwong

    In order to reduce sewage sludge of concentrated natural rubber latex (CNRL) and transform it into a valuable material for efficient removal of Al3+ and Cu2+ ions from wastewater, magnetic biochar was prepared. In this work, sewage sludge from CNRL was pyrolyzed at various temperatures (300–700 °C) to assess the effects of pyrolysis temperature on the efficiency of magnetic biochar in removing Al3+ and Cu2+ ions from an aqueous medium. Effect of the chemical composition of sewage sludge on the biochar characteristic was evaluated. Sewage sludge is mainly organic matter. The mineral elements silicon (Si), phosphorus (P), sulfur (S) and calcium (Ca) were also observed in the sewage sludge. With increasing pyrolysis temperature, the contents of P and potassium (K) increased. The inorganic metals chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni) and lead (Pb) were present in small quantities. Pyrolysis temperatures 400–500 °C provided good quality magnetic biochar, while with the higher 700 °C pyrolysis temperature, specific surface area and pore volume decreased. The prepared biochar had combined meso- and macro-porous structure. Isotherms of Type II were indicating multilayer adsorption on porous biochar. The pseudo-second-order kinetic models described well Al3+ and Cu2+ adsorption onto magnetic biochar. The leaching test of magnetic biochar shows the releasing of K and Zinc (Zn) which can effect on the sorption of Al3+ and Cu2+. The binding mechanism between magnetic biochar and Al3+/Cu2+ involved surface complexation, ion exchange and cation‒π interaction.

    更新日期:2020-01-09
  • Impacts of nanoscale zero-valent iron on nitrite accumulation performance of nitritation granular sludges with different spatial morphologies and its biosorption behavior
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-09-24
    Jianfang Wang, Jiayi Sheng, Feiyue Qian, Xiaoqing Ji, Honggui Yin, Junxia Wang

    To explore the potential impacts of nanoscale zero-valent iron (nZVI) particles on nitrite accumulation performance of nitritation granular sludge (NGS), two types of NGS (NGSA and NGSH) with different spatial morphologies were employed to exposure under a wide dosage of nZVI in batch tests. The biosorption behavior of nZVI was also investigated by determining adsorption isotherm. Results showed that the ecotoxic effect of nZVI was ascribed to its fast adsorption to the granules. Although NGSA and NGSH shared a similar bacterial community structure dominated by genus Nitrosomonas based on high-throughput pyrosequencing, the compact and small granules of NGSA showed a stronger tolerance for nZVI exposure than NGSH with loose spatial structure. The 50% inhibition dosage of nZVI for ammonium-oxidizing bacteria activity in NGSA and NGSH was 88.5 and 21.3 mg g−1 VSS, respectively. As a crucial self-protection mechanism of microbes, the secretion of extracellular polymeric substances was dramatically enhanced with nZVI exposure at a low dosage, and a simultaneous decrease in both extracellular polymeric substances contents and ammonium-oxidizing activity of NGS was observed with a high accumulation of total iron in sludge phase. Overall, the results suggested that ammonium-oxidizing bacteria in granules were susceptible to inhibition by nZVI exposure, and release of engineered nanoparticles into wastewater treatment system increased the risk of failure in autotrophic nitrogen removal process.

    更新日期:2020-01-09
  • A convenient approach directly from triglycerides toward the producing of thia -wax esters as bio- and chemical raw materials
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-08-02
    Ayhan Yıldırım, Kaan Kıraylar, Serkan Öztürk

    Practical and efficient method has been developed for the preparation of novel sulfur-containing esters from triglycerides as potential important industrial and biomaterials. The fact that these unusual compounds are not found in natural sources encourages both academic and industrial communities for their preparation with suitable chemical or enzymatic processes. In general, enzymatic processes requiring more laborious synthesis and product isolation stages. On the other hand, known chemical methods for the preparation of normal wax esters have several drawbacks cited in the present work. Therefore, the chemical method developed in the present study is environmentally benign and suitable for both small- and large-scale syntheses of normal and unusual wax esters. For this purpose, triglycerides were taken to the transesterification reaction in a solvent-free medium with synthetic thia-long-chain alcohols at a ratio of (1:3). In order to catalyze the reaction, newly synthesized bis-imidazole-based metal-free acidic ionic liquid was used and the thia-mono esters were obtained in a fairly short period of time (6 h) with good to excellent yields. The catalyst reuse and large-scale synthesis studies were also carried out.

    更新日期:2020-01-09
  • Design of Fe-MOF-bpdc deposited with cobalt oxide (CoO x ) nanoparticles for enhanced visible-light-promoted water oxidation reaction
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-08
    Shinya Mine, Zakary Lionet, Haruka Shigemitsu, Takashi Toyao, Tae-Ho Kim, Yu Horiuchi, Soo Wohn Lee, Masaya Matsuoka

    This work spotlights the facile method to deposit cobalt oxide (CoOx) nanoparticles as a cocatalyst on Fe-MOF-bpdc to enhance its photocatalytic activity for water oxidation reaction (WOR) under visible light irradiation to evolve gaseous O2. Due to the soft conditions needed for the process developed, the framework structure of Fe-MOF-bpdc was maintained even after the deposition of CoOx. The optimized CoOx@Fe-MOF-bpdc composite showed enhanced activity towards visible-light-driven WOR as compared to pristine Fe-MOF-bpdc, the amount of evolved O2 being increased by about 2 times at the maximum with CoOx loading of 2 wt% as Co metal. Investigations on the wavelength dependence of visible-light-driven WOR on CoOx@Fe-MOF-bpdc revealed that the direct photo-excitation of Fe-oxo clusters within Fe-MOF-bpdc plays an important role to initiate the reaction. Furthermore, it was found that the rate of 2-propanol oxidation reaction, which is a typical two-electron oxidation reaction, was hardly affected by CoOx deposition, suggesting that CoOx acts as a unique hole trapping site and more preferentially catalyse the four-electron oxidation reactions like WOR than the two-electron oxidation reaction.

    更新日期:2020-01-08
  • Study of three-component reaction of α-ketoesters and active methylenes with OH -acids to synthesize new 2-amino-4 H -pyran derivatives and evaluation of their antibacterial and antioxidant activities
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-08
    Mahyar Aghajani, Sakineh Asghari, Ghasem Firouzzadeh Pasha, Mojtaba Mohseni

    Synthesis of new derivatives of 2-amino-4H-pyrans is reported via three-component reaction of α-ketoesters, active methylenes, and OH-acids in the presence of catalytic amount of piperidine at room temperature with high to excellent yields. The structure of synthesized compounds was characterized by FTIR, 1H, 13C NMR spectroscopy, and mass spectrometry. Simplicity of procedure, mild reaction conditions, short reaction time, and easy separation of the products make this an interesting alternative to other reported approaches. Also, their antibacterial and antioxidant activities were evaluated against Staphylococcus aureus and Bacillus subtilis as Gram-positive bacteria and Escherichia coli and Pseudomonas aeruginosa as Gram-negative bacteria, as well as the radical scavenger DPPH. Among these compounds, 4l including CO2Et substituent and 6-methyl-2H-pyran-2-one moiety showed the highest antioxidant and antibacterial activities.

    更新日期:2020-01-08
  • Synthesis, characterization, and antioxidant activity of some new N 4 -arylsubstituted-5-methoxyisatin- β -thiosemicarbazone derivatives
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-08
    Halit Muğlu

    Firstly, thiosemicarbazides were prepared by the reaction of hydrazine monohydrate with isothiocyanates in cold dry ethanol at 0 °C for 1 h. After that, new isatin-β-thiosemicarbazones were synthesized by treatment of 5-methoxyisatin with thiosemicarbazides in aqueous ethanol containing one drop of hydrochloric acid at reflux for 3 h. The chemical structures of products were confirmed by means of IR, 1H NMR, and 13C NMR data and by elemental analysis. All the synthesized compounds were evaluated for their antioxidant activity by 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging method. The synthesized molecules showed lower antioxidant activity than the standard Trolox (8.757 μM). IC50 values of the newly synthesized isatin-β-thiosemicarbazone derivatives ranged from 12.455 to 73.471 μM.

    更新日期:2020-01-08
  • Novel biogenic silver nanoparticles used for antibacterial effect and catalytic degradation of contaminants
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-06
    T. My-Thao Nguyen, T. Thanh-Tam Huynh, Chi-Hien Dang, Dinh-Tri Mai, T. Thuy-Nhung Nguyen, Dinh-Truong Nguyen, Van-Su Dang, Trinh-Duy Nguyen, Thanh-Danh Nguyen

    The study reports a versatile, cost-efficient and ecofriendly protocol for the synthesis of biogenic silver nanoparticles (AgNPs) using the aqueous extracts of Quao Binh Chau, Stereospermum binhchauensis and Che Vang, Jasminum subtriplinerve and their application in antibacterial activity and catalysis. The AgNPs with varying morphology and physical properties have been optimized using the absorption measurements. The biogenic AgNPs have been characterized by Fourier transform infrared spectroscopy, UV–Vis spectroscopy, transmission electron microscopy, X-ray diffraction analysis, energy-dispersive X-ray spectroscopy and thermal behaviors. Stable crystalline AgNPs with average particle sizes of 20.0 nm and 8.0 nm were fabricated from aqueous extract of Quao Binh Chau and Che Vang, respectively. The phytochemicals from the extracts involved in reduction and stabilization of AgNPs are identified by FTIR spectra and thermal gravimetric analysis. Both the biosynthesized AgNPs show the potent antibacterial activity against four tested bacterial strains including Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Agrobacterium tumefaciens. High catalytic activity of the biogenic AgNPs in the degradation of toxic contaminants (4-nitrophenol and methyl orange) was observed. The antibacterial and catalytic activities are found to be size and phytochemical dependent. The antibacterial and catalytic activities of the biogenic nanoparticles would find applications in the biomedical and environmental fields.

    更新日期:2020-01-06
  • A simple, rapid and effective protocol for synthesis of bis(pyrazolyl)methanes using nickel–guanidine complex immobilized on MCM-41
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-06
    Alireza Kohzadian, Hossein Filian, Zahra Kordrostami, Abdolkarim Zare, Arash Ghorbani-Choghamarani

    Abstract In this paper, a rapid, easy and very efficient method for the synthesis of bis(pyrazolyl)methanes has been reported in the presence of nickel–guanidine complex immobilized on MCM-41 (MCM-41@Gu@Ni) as a recyclable nanocatalyst. This mesoporous silica catalyst was effective for the one-pot multi-component reaction of arylaldehydes, phenylhydrazine and ethyl acetoacetate in ethanol solvent. The current synthesis shows attractive features, for example the use of recoverable and reusable nanocatalyst (5 times), easy workup, suitable one-pot procedure, short reaction times, good to excellent yields and moderate reaction conditions. Graphic abstract

    更新日期:2020-01-06
  • PrCo 1−x Fe x O 3 perovskite powders for possible photocatalytic applications
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-06
    V. Sydorchuk, I. Lutsyuk, V. Shved, V. Hreb, A. Kondyr, O. Zakutevskyy, L. Vasylechko

    Abstract Mixed perovskites PrCo1−xFexO3 have been synthesized by the solgel citrate route with the following calcinations in air at 600–800 °C. The prepared samples have been studied using DTA–TG, XRD, FTIR and UV–Vis spectroscopy, and nitrogen low-temperature adsorption–desorption. Electronic structure and magnetic properties of the mixed praseodymium cobaltites–ferrites were calculated within the projector augmented wave method, implemented in the ABINIT software package. The prepared perovskites have been tested as photocatalysts of dyes degradation under visible illumination. It has been established that only the crystalline perovskite phase is photocatalytically active. The prepared materials are semiconductors with band gap within 1.7–2.6 eV and intense absorption of visible light. This fact as well as sufficiently high specific surface area and developed meso–macroporous structure ensures their increased photocatalytic activity. The most active in the PrCo1−xFexO3 series is the sample with Co/Fe = 1:9 due to the highest specific surface area, low value of the band gap, and higher deformation of orthorhombic perovskite structure.

    更新日期:2020-01-06
  • One-step biological synthesis of cauliflower-like Ag/MgO nanocomposite with antibacterial, anticancer, and catalytic activity towards anthropogenic pollutants
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-04
    M. Jayapriya, K. Premkumar, M. Arulmozhi, K. Karthikeyan

    The present research work explores an environmental benign, lucrative approach for the synthesis of cauliflower-like Ag/MgO nanocomposite using Musa paradisiaca bract extract (MPBE) with multifunctional efficiency towards antibacterial, anticancer, and catalytic degradation towards methylene blue (MB), methyl orange (MO), and O-nitrophenol (O-Nip). The UV–visible absorption spectra of the synthesized Ag/MgO nanocomposite exhibit absorption peak at 270 nm and 410 nm, respectively. Fourier transform infrared spectroscopy was used to probe the functional biomolecules responsible for the reduction of Ag/MgO nanocomposite. The X-ray diffraction spectroscopy and the surface morphological images revealed the successful formation of cauliflower-like Ag/MgO nanocomposite. The fabricated nanocomposite exhibited potent antibacterial and anticancer activity for human pathogenic organisms Escherichia coli and Staphylococcus aureus with zone of inhibition 15 mm and 14 mm and showed IC50 value of 190 μg/ml against A549 cells. Apoptosis assay (AO/EB staining) was carried out, and the obtained results showed that bright green fluorescence indicates early apoptosis, red to orange fluorescence indicates late apoptosis, and red fluorescence denotes necrosis. Also the synthesized Ag/MgO nanocomposite exhibits enhanced catalytic degradation of 91%, 95%, and 98% in 6 min, 9 min, and 10 min for MB, MO, and O-Nip. Hence, this study highlights the use of MPBE for effective fabrication of cauliflower-like Ag/MgO nanocomposite with multifaceted application that acts as a potential candidate to resolve the diverse problems.

    更新日期:2020-01-04
  • Efficient removal of oil pollutant via simultaneous adsorption and photocatalysis using La–N–TiO 2 –cellulose/SiO 2 difunctional aerogel composite
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-04
    Jun Zhao, Xiaoyu Chen, Yuhan Zhou, Hongjing Tian, Qingjie Guo, Xiude Hu

    Abstract Nano-TiO2 photocatalysts doped with La–N(La–N–TiO2) were prepared by solgel method. The La–N–TiO2 was loaded on the cellulose/SiO2 composite aerogel (La–N–TiO2–CSA). La–N–TiO2–CSA had both oil absorption and oil degradation functions under the sun. The static state water contact angle is up to 148° close to superhydrophobic surface. An apparent decomposition rate of oil is 92%, which is much higher than 26% of pure TiO2. Under the visible light irradiation, the photocurrent density has increased by 50%. Characterization results show that LaONO3 was uniformly distributed in TiO2 crystal. Compared with pure TiO2, the UV–Vis DRS data showed the absorption band of La–N–TiO2 had extended to 441 nm. The La increased the valence band position and N lowered the conduction band position, which reduced the band gap of TiO2 from 3.59 to 2.81 eV. The formation of LaONO3 reduced carrier transfer resistance, and the migration rate and electron–hole separation efficiency were improved. The possible oil decomposition pathways were proposed. Graphic abstract

    更新日期:2020-01-04
  • Functionalization of sheet structure Co–Mo–S with Ni(OH) 2 for efficient photocatalytic hydrogen evolution
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2020-01-01
    Jing Xu, Min Mao, Hai Yu

    In this paper, the new composite material Co–Mo–S/Ni(OH)2 has high hydrogen evolution ability under photoreaction, the hydrogen evolution of Co–Mo–S/Ni(OH)2 composite material reaches 357 μmol after reaction 3 h, and the catalyst still exhibits high photocatalytic activity after four cycles under light response. It shows that this new catalyst has high activity and stability. The results of XPS, TEM, SEM and XRD indicate that the composite catalyst is successfully synthesized. The results of PL and electrochemical experiments show that Ni(OH)2 attached to Co–Mo–S can increase the transfer of photogenerated electrons and reduce the recombination of electrons and holes. From the UV–visible and BET characterization, the presence of Ni(OH)2 increases the range of response of the Co–Mo–S to sunlight, the pore volume and surface range, which improves the absorption capacity of the catalyst for ErB. Therefore, Co–Mo–S/Ni(OH)2 has excellent application prospect.

    更新日期:2020-01-01
  • Synthesis and characterization of activated carbon@zerovalent iron–nickel nanoadsorbent for highly efficient removal of Reactive Orange 16 from aqueous sample: experimental design, kinetic, isotherm and thermodynamic studies
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-12-20
    Maryam Sadat Seyedi, Mahmoud Reza Sohrabi, Fereshte Motiee, Saeid Mortazavinik

    A simple and fast method based on activated carbon@nanozerovalent iron–nickel (AC@nZVI/Ni) nanoadsorbent was developed for highly efficient removal of Reactive Orange 16 (RO16) from aqueous samples. AC@nZVI/Ni nanoadsorbent was characterized by FT-IR, XRD, SEM and EDX. Effects of diverse factors including the solution value, adsorption time, AC@nZVI/Ni dosage and initial RO16 concentration were explored via experimental design methodology, and the highest removal percentage of 100% was obtained under the optimal conditions. Langmuir and Freundlich models were employed to interpret the equilibrium adsorption data by utilizing different initial concentrations of RO16. The data are fitted to the Langmuir model, with a maximum adsorption capacity of 10.53 mg g−1 and a Langmuir constant of 13.51 L mg−1. The kinetic data were fitted to the pseudo-second-order model. Finally, thermodynamic study was accomplished at diverse temperatures and the data revealed an exothermic nature.

    更新日期:2019-12-20
  • One-step synthesis of an environment-friendly cyclodextrin-based nanosponge and its applications for the removal of dyestuff from aqueous solutions
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-12-20
    Liuxing Li, Huijun Liu, Wei Li, Kai Liu, Ting Tang, Juan Liu, Wenkang Jiang

    Cyclodextrin-based nanosponges (CDNS) are a novel kind of polymers belonged to cross-linked derivatives of cyclodextrins, and they are safe, biodegradable materials with appreciable toxicity to the environment. In this work, CDNS were fabricated in one-step solvothermal method by β-cyclodextrin (β-CD) and diphenyl carbonate (DPC), for the removal of dyestuffs from wastewater using two of the familiar dyes as the model contaminant. It was systematically investigated by the influence of the amount of adsorbent, the molar ratio of β-CD and DPC, pH, time, and initial concentration. Experimental results showed the maximum adsorption capacities of Basic red 46 and Rhodamine B were 101.43 mg/g and 52.33 mg/g, the adsorption behavior of two contaminants followed pseudo-second-order model and the Langmuir monolayer adsorption models. The differences in adsorption capacities on two model contaminants might due to the influence of dye structure. In conclusion, cyclodextrin-based nanosponges are a promising kind of environment-friendly materials in water treatment.

    更新日期:2019-12-20
  • High activity of Pt–Rh supported on C–ITO for ethanol oxidation in alkaline medium
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-12-18
    V. F. de Carmargo, E. H. Fontes, J. Nandenha, R. F. B. de Souza, A. O. Neto

    PtRh/C–ITO electrocatalysts were prepared in a single-step method using H2PtCl6·6H2O and RhCl3·xH2O as metal sources, sodium borohydride as the reducing agent and a physical mixture of 85% Vulcan Carbon XC72 and 15% In2O3·SnO2 (indium tin oxide—ITO) as support. PtRh/C–ITO were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), cyclic voltammetry, chronoamperommetry, attenuated total reflectance, Fourier transform infrared spectroscopy and performance test on direct alkaline ethanol fuel cell. X-ray diffraction patterns for all PtRh/C–ITO indicated a shift in Pt (fcc) peaks, showing that Rh was incorporated into Pt lattice. Transmission electron microscopy for PtRh/C–ITO showed nanoparticles homogeneously distributed over the support with particles size between 3.0 and 4.0 nm. The XPS results for Pt70Rh30/C–ITO showed the presence of mixed oxidation states of Sn0 and SnO2 that could favor the oxidation of adsorbed intermediates by bifunctional mechanism. Pt90Rh10/C–ITO was more active in electrochemical studies, which could be associated with the C–C bond break. Experiments in direct alkaline ethanol fuel cells showed that the power density values obtained for Pt70Rh30/C–ITO and Pt90Rh10/C–ITO were higher than Pt/C, indicating the beneficial effect of Rh addition to Pt and the use of C–ITO support.

    更新日期:2019-12-19
  • Preparation and characterization of MNPs–PhSO 3 H as a heterogeneous catalyst for the synthesis of benzo[ b ]pyran and pyrano[3,2- c ]chromenes
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-12-16
    Homayoun Faroughi Niya, Nourallah Hazeri, Mahboobeh Rezaie Kahkhaie, Malek Taher Maghsoodlou

    In this study, an efficient and novel procedure has been reported for loading sulfanilic acid on the surface of magnetite Fe3O4 nanoparticles using tris(hydroxymethyl) aminomethane and 1,2-dichloroethane. Next, the synthesized nanocatalyst was fully characterized using FT-IR, XRD, TGA, VSM, SEM, and TEM. The results show that the synthesis of magnetic nanocatalyst has been successful with a range of 2–20 nm in size. Finally, the catalytic activity of this superparamagnetic nanocatalyst was explored for the synthesis of tetrahydrobenzo[b]pyran and 2-amino-5-oxo-4,5-dihydropyrano[3,2-c]chromene-3-carbonitrile derivatives. The synthesized nanocatalyst has advantages such as non-toxicity, short reaction time, easy workup, cleaner reaction profiles under mild reaction conditions.

    更新日期:2019-12-17
  • Syngas production from methane steam reforming and dry reforming reactions over sintering-resistant Ni@SiO 2 catalyst
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-12-13
    Bolin Han, Fagen Wang, Linjia Zhang, Yan Wang, Weiqiang Fan, Leilei Xu, Hao Yu, Zhongcheng Li

    Syngas is a very important intermediate in chemical industry for energy chemicals production through F–T synthesis. Methane steam reforming (MSR) and dry reforming (MDR) reactions are two extensively studied approaches for syngas production. Developing sintering-resistant catalyst for syngas production from the reforming reactions is a hot topic because high-temperature requirement for the reactions always deactivates catalyst due to sintering and carbon deposition. In this study, we synthesized sintering-resistant Ni@SiO2 catalyst for stable performances of MSR and MDR. Characterization of TEM, XRD, etc., revealed that the Ni@SiO2 catalyst could maintain original core–shell structure and preserve Ni nanoparticle size at temperature as high as 1123 K. The excellent sintering resistance was attributed to encapsulation of thermally stable SiO2 nanospheres, which confined Ni nanoparticles migration and thus avoided aggregation. The work provided a potential sintering-resistant catalyst for heterogeneous reactions.

    更新日期:2019-12-13
  • WN/nitrogen-doped reduced graphite oxide hybrids for triiodide reduction in dye-sensitized solar cells
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-12-12
    Xiuwen Wang, Qi Sun, Lihong Qi

    The development of low-cost, environmental friendliness, outstanding catalytic activity, superior conductivity and good stability counter electrode (CE) catalyst in dye-sensitized solar cells (DSSCs) is important to promote the commercial application of DSSCs. Here, WN/nitrogen-doped reduced graphite oxide hybrids (WN/NrGO) had been synthesized by hydrothermal method followed by nitridation treatment, which used as CE catalysts for catalyzing I3− to I−. The combined WN and nitrogen-doped reduced graphite oxide (NrGO) into WN/NrGO could effectively regulate the catalytic activity for the reduction of I3−, accelerate the charge transfer at the interface, and then the synergistic effect between of them can be fully achieved. When the WN/NrGO served as the CE catalyst in DSSCs, the photoelectric conversion efficiency (PCE) of 7.42% has been obtained, compared to the conventional Pt-based DSSCs (7.71%). Meanwhile, as-prepared WN/NrGO exhibited higher PCE than that of the solo WN (6.19%) and NrGO (5.81%) in parallel. A series of electrochemical measures revealed that the WN/NrGO displayed the higher catalytic activity and charge transfer ability than that of the solo WN and NrGO, so the synthesized low-cost WN/NrGO have an potential to be used as the effectively CE catalysts for the replacement of the noble Pt.

    更新日期:2019-12-13
  • Design, synthesis, characterization and catechol oxidase activity of novel class of multi-tripodal pyrazole and triazole-based derivatives
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-12-09
    Abdelkhalek Zerrouki, Farid Abrigach, Mustapha Taleb, Sghir El Kadiri

    A class of novel multi-tripodal ligands has been prepared via condensation reaction between pyrazole or triazole moieties and N′,N′-bis(2-aminoethyl)ethane-1,2-diamine. Spectroscopic techniques (1H NMR, 13C NMR, IR and mass spectroscopy) have been used to characterize the compounds. The ability of the in situ ligand complexes to catalyze the oxidation reaction of catechol to o-quinone at ambient conditions has been studied. The study demonstrated that the concentration of the metal salt has a pronounced influence on the catalytic activity. Thus, the best result has been obtained with the in situ complex [2 + CuSO4] with an oxidation rate of 21.60 µmol l−1 min−1. Kinetic parameters of the in situ complexes have been also investigated.

    更新日期:2019-12-11
  • Layered double hydroxides@poly( p -phenylenediamine)@Cu as a novel catalyst for the synthesis of pyrrole derivatives: preparation and characterization
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-12-04
    Maryam Mirzaei-Mosbat, Ramin Ghorbani-Vaghei, Zahra Karamshahi

    In this research, the synthesis route of ZnCr-layered double hydroxides functionalized with poly(p-phenylenediamine) and Cu(II) was described. LDHs@PpPDA@Cu was synthesized as a novel, green, and recyclable catalyst and characterized by various techniques including Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetry analysis, X-ray diffraction, and energy dispersive X-ray analysis. The catalytic activity of the LDHs@PpPDA@Cu was investigated in the synthesis of pyrrole derivatives via one-pot four-component coupling of amine, aldehyde, nitromethane and acetylacetone. The results of analyses demonstrated that the reactions proceeded to completion which has led to the successful synthesis of high purity compounds.

    更新日期:2019-12-11
  • Design and synthesis of novel ditopic ligands with a pyrazole ring in the central unit
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-12-03
    Bogdan-Ionel Bratanovici, Alina Nicolescu, Sergiu Shova, Ioan-Andrei Dascălu, Rodinel Ardeleanu, Vasile Lozan, Gheorghe Roman

    Four novel ditopic ligands that have a pyrazole ring in their central unit and are useful for the generation of coordination polymers have been synthesized. Two of these ditopic ligands present two carboxylate functions as coordinating groups, while the other two are hybrid ligands having only one carboxylate function and either tetrazolate or imidazole as the remaining coordination site. The ligands have been obtained through a multi-step reaction sequence that begins with the Claisen condensation of either 4-acetylbenzonitrile or 4-(1H-imidazol-1-yl)acetophenone with diethyl oxalate and has the Knorr pyrazole ring closure as its key step. Subsequently, the tetrazolate in one of the ligands is constructed through a [3 + 2] cycloaddition of azide anion to the cyano group, while hydrolysis of the ester and the cyano substituents generates the carboxylate function(s). The structure of the intermediates and of the target ligands has been investigated by solution NMR, special attention being given to keto–enol and pyrazole tautomerism when present. The structure of two ligands and a key intermediate has also been established by single-crystal X-ray diffraction.

    更新日期:2019-12-11
  • Reactivity of N -substituted alkenylidene hydrazinecarbothioamides toward tetracyanoethylene, an efficient synthesis stereoselective 1,3-thiazole compounds
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-12-02
    Alaa A. Hassan, Ashraf A. Aly, Nasr K. Mohamed, Kamal M. El-Shaieb, Maysa M. Makhlouf, Stefan Bräse, Martin Nieger, Alan B. Brown

    The reaction between N-substituted alkenylidene hydrazinecarbothioamides and two molar amounts of tetracyanoethylene (TCNE) in anhydrous THF at room temperature without using any catalyst affords (Z)-4-amino-3-((Z)substituted amino)-2-(substituted imino)-2,3-dihydrothiazole-5-carbonitriles and (Z)-(4-amino-5-cyano-thiazol-2(3H)-ylidene)carbonhydrazonoyl dicyanides. Rationales for these transformations are presented. The structures of the obtained products were confirmed via single-crystal X-ray analyses.

    更新日期:2019-12-11
  • An EPR characterisation of stable and transient reactive oxygen species formed under radiative and non-radiative conditions
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-10-21
    E. Richards, D. M. Murphy, M. Che

    Electron paramagnetic resonance (EPR) spectroscopy is the ideal method of choice when detecting and studying the wide variety of paramagnetic oxygen-centred radicals. For simple diatomic radicals, such as the superoxide (O2−) or peroxy \( ({\text{ROO}}^{\bullet})\) species, the CW EPR profile (in particular the g-values) of these species can appear similar and indeed indistinguishable in some cases. Experiments using 17O-enriched oxygen, revealing a rich 17O hyperfine pattern, are therefore essential to distinguish between the two species. However, in many cases, particularly involving TiO2 photocatalysis, the peroxy-type \( ({\text{ROO}}^{\bullet})\) radicals or other intermediate species such as the [O2−…organic]-type adducts can be transient in nature and once again can produce similar g-values. In general terms, these reactive oxygen species (ROS) are formed and detected at low-temperature conditions. Hence, the application of EPR spectroscopy to studies of surface-stabilised oxygen-centred radicals must be performed under carefully selected conditions in order to confidently distinguish between the differing types of diatomic radicals, such as O2−, \( {\text{ROO}}^{\bullet}\) or [O2−…organic].

    更新日期:2019-12-11
  • Synthesis and biological activity of novel 1,3,4-oxadiazole derivatives containing a pyrazole moiety
    Res. Chem. Intermed. (IF 2.064) Pub Date : 2019-10-15
    Wei Yu, Zhi-Wen Zhai, David E. Wedge, Stephen O. Duke, Hong-Ke Wu, Jian-Quan Weng, Cheng-Xia Tan, Yong-Gang Zhang, Xing-Hai Liu

    Several new 1,3,4-oxadiazole derivatives containing a pyrazole ring were designed and synthesized from ethyl acetoacetate and triethyl orthoformate as starting materials via multi-step reactions. The compound structures were confirmed by melting point, 1H NMR and HRMS. They were evaluated for fungicidal and herbicidal activities. Four of the compounds exhibited moderate fungicidal activity against Colletotrichum species. Most of the compounds had moderate-to-good activity as a herbicide.

    更新日期:2019-12-11
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