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排序方式: 共有161条查询结果,搜索用时 31 毫秒
1.
M. Zendehdel A. Mobinikhaledi F. Hasanvand Jamshidi 《Journal of inclusion phenomena and macrocyclic chemistry》2007,59(1-2):41-44
Transition metal/Y zeolites were prepared using microwave solid state and aqueous solution ion exchange methods. The activity
of these zeolites was investigated in a conversion of acids to benzimidazoles reaction between 4-methyl-1, 2-phenylenediamine and 3-nitrobenzoic acid. The yield of these reactions increased in order of CuY < Fe2+Y < NiY < CoY < NaY < CrY < MnY < ZnY for both methods. The solid state ion-exchanged zeolites showed higher activity in comparison
to the aqueous solution exchange. Yields of products in the presence of the ZnY zeolite were of the order of 69–83%. It seems
that the Lewis sites are better sites compared to the Bronsted sites for this reaction. 相似文献
2.
JPC – Journal of Planar Chromatography – Modern TLC - A new stability-indicating HPTLC assay has been established for leuprolide acetate. Silica gel 60F254 was used as stationary phase.... 相似文献
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Preparation and characterization of Cu (II) supported on poly(8‐hydroxyquinoline‐p‐styrene sulphonate) and its application as catalyst for the synthesis of hexahydroquinolines
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Ardeshir Khazaei Mahsa Tavasoli Vahid Jamshidi Fatemeh Gohari Ghalil Ahmad Reza Moosavi‐Zare 《应用有机金属化学》2018,32(7)
Cu ( II ) supported on poly(8‐hydroxyquinoline‐p‐styrenesulfonate) (Cu ( II )@PHQSS) was prepared and fully characterized by the different techniques including fourier transform infrared spectroscopy (FT‐IR), 1H NMR, 13C NMR, thermal gravimetric analysis (TGA), differential thermal gravimetric (DTG), differential thermal analysis (DTA), scanning electron microscope (SEM) and energy dispersive X‐ray analysis (EDS). Afterward, the Cu ( II )@PHQSS as nanostructured catalyst was used as catalyst for the synthesis of hexahydroquinolines. 相似文献
5.
Niloufar Afzali Reihaneh Kardanpour Farnaz Zadehahmadi Shahram Tangestaninejad Majid Moghadam Valiollah Mirkhani Adam Mechler Iraj Mohammadpoor‐Baltork Mehrnaz Bahadori 《应用有机金属化学》2019,33(11)
A novel heterogeneous nanocatalyst was established by supporting molybdenum (VI) on Zr6 nodes in the structure of the well‐known UiO‐66 metal–organic framework (MOF). The structure of the UiO‐66 before and after Mo (VI) immobilization was confirmed with XRD, DR‐FTIR and UV–vis spectroscopy, and the presence and amount of Mo (VI) was identified by X‐ray photoelectron spectroscopy and inductively coupled plasma atomic emission spectroscopy. TEM imaging confirmed the absence of Mo clusters on the MOF surface, while SEM confirmed that the appearance of the MOF has not changed upon immobilizing the Mo (VI) catalyst. BET adsorption measurements were used to confirm the porosity of the catalyst. The catalytic activity of this heterogeneous catalyst was investigated in oxidation of sulfides with H2O2 in acetonitrile and oxidative desulfurization of dibenzothiophene. Easy work up, convenient and steady reuse and high activity and selectivity are prominent properties of this new hybrid material. 相似文献
6.
Masoumeh Taei Foroozan Hasanpour Mohammad Dinari Nasrin Sohrabi Mohammad Sadegh Jamshidi 《中国化学快报》2017,28(2):240-247
In this study,Au nanoparticles/poly 5-[(2-hydroxynaphthalen-l-yl)diazenyl]isophthalic acid film modified glassy carbon electrode(AuNPs/poly(NDI)/GCE) has shown excellent electrocatalytic activity toward the oxidation of adrenaline(ADR),paracetamol(PAC),and tryptophan(Trp).The bare glassy carbon electrode(GCE) fails to separate the oxidation peak potentials of these molecules,while the poly(NDI) film modified electrode can resolve them.Electrochemical impedance spectroscopy(EIS)indicates that the charge transfer resistance of the bare electrode decreases as 5-[(2-hydroxynaphthalen-l-yl)diazenyl]isophthalic acid is electropolymerized on the bare electrode.Furthermore,EIS exhibits enhancement of electron transfer kinetics between analytes and the electrode after electrodeposition of Au nanoparticles.Differential pulse voltammetry results show that the electrocatalytic current increases linearly in the ranges of 0.01-680.0 μmol L~1 for ADR,0.05-498.0 μmol L~1 for PAC,and 3.0-632.0 μmol L~1 for Trp;with detection limits(S/N = 3) of 0.009 μmol L~1,0.005 μmol L~1,and 0.09 μmol L~1 for ADR,PAC,and Trp,respectively.The proposed method has been successfully applied for simultaneous determination of ADR,PAC,and Trp in biological samples. 相似文献
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Rasool Jamshidi Zahra Afzali 《International journal of environmental analytical chemistry》2013,93(9):821-827
A procedure has been proposed for the separation and preconcentration of trace amounts of thallium. It is based on the adsorption of thallium ions onto organo nanoclay loaded with 1-(2-pyridylazo)-2-naphthol (PAN). Thallium ions were quantitatively retained on the column in the pH range of 3.5–6.0, whereas quantitative desorption occurs with 5.0?mL of 5% ascorbic acid and thallium was determined by flame atomic absorption spectrometry. Linearity was maintained between 0.66?ng?mL?1–15.0?µg?mL?1?in initial solution. Detection limit was 0.2?ng?mL?1?in initial solution and preconcentration factor was 150. Eight replicate determinations of 2.0?µg?mL?1 of thallium in final solution gave a relative standard deviation of ±1.48%. Various parameters have been studied, such as the effect of pH, breakthrough volume and interference of a large number of anions and cations and the proposed method was used to determine thallium ions in water and standard samples. Determination of thallium ions in standard sample showed that the proposed method has good accuracy. 相似文献
9.
A polymerized film of Adizol Black B (ABB) on the surface of glassy carbon (GC) electrode was prepared for the simultaneous determination of ascorbic acid (AA), epinephrine (EP), and uric acid (UA). This new electrode presented an excellent electrocatalytic activity towards the oxidation of AA, EP, and UA by differential pulse voltammetry method. The oxidation peaks of the three compounds were well defined and had the enhanced peak currents. The separation of the oxidation peak potentials for AA–EP and EP–UA were about 180 and 130 mV, respectively. The calibration curves obtained for AA, EP, and UA were in the ranges of 2.0–1,970.0, 0.1–64.0, and 0.1–1,700.0 μmol L–1, respectively. The detection limits (S/N?=?3) were 0.01, 0.007, and 0.02 μmol L–1 for AA, EP, and UA, respectively. The diffusion coefficient and the catalytic rate constant for the oxidation reaction of EP at poly(ABB) film-coated GC electrode were calculated as 1.54(±0.10)?×?10?4 cm2 s?1 and 4.5?×?103 mol?1 L s?1, respectively. The present method was applied to the determination of EP in pharmaceutical, AA in commercially available vitamin C tablet, and UA in urine samples. 相似文献
10.
Research on Chemical Intermediates - A highly efficient magnetic adsorbent is presented to preconcentrate acid violet-7 (AV-7) prior quantifying by UV–visible spectroscopy... 相似文献