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排序方式: 共有199条查询结果,搜索用时 468 毫秒
81.
Hassan Hosseini-Monfared Afsaneh Farrokhi Sohaila Alavi Peter Mayer 《Transition Metal Chemistry》2013,38(3):267-273
A mononuclear dioxo vanadium(V) complex of a hydrazone ONO donor ligand, [VVO2(L1)] (1), was synthesized by the reaction of V2O5 and terephthalic acid with H2L1 in 1:1:1 mol ratio, while an oxo-bridged bis(vanadium(IV)oxo) complex, [μ 2–O–{VIVO(L2)}2] (2), was synthesized by the treatment of isonicotinic acid hydrazide, salicylaldehyde and CoSO4·7H2O with bis(acetylacetonato)oxovanadium(IV) (H2L1 = isonicotinic acid(2-hydroxy-benzylidene)-hydrazide, H2L2 = isonicotinic acid (1-methyl-3-oxo-butylidene)-hydrazide). The complexes were characterized by elemental analyses and spectroscopic methods. The crystal structure of complex 2 was determined by X-ray analysis. The complexes were tested as catalysts for the oxidation of cycloalkenes and benzyl alcohol using H2O2 as terminal oxidant. Excellent selectivity was achieved in the oxidation of cyclohexene. 相似文献
82.
In the present paper, the electrochemical reduction of nitrite at a hemoglobin modified pencil lead electrode (Hb/PLE) is described. The electrochemical properties of nitrite were studied by cyclic voltammetry and chronoamperometry. Results showed that the hemoglobin film has an excellent electrochemical activity towards the reduction of nitrite. By using voltammetric and chronoamperometric methods, α, nα and n were calculated. Then the ability of the electrode for nitrite determination was investigated using differential pulse voltammetry. The electrocatalytic reduction peak currents were found to be linear with the nitrite concentration in the range from 10 to 220 µM with a detection limit of 5 µM. The relative standard deviation is 2 % for 3 successive determinations of a 100 µM nitrite solution. This modified electrode was successfully used for the detection of low amounts of NO2? in spinach sample and a spiked sample of tap water. 相似文献
83.
Mohammad Mazloum-Ardakani Mahboobe Abolhasani Bibi-Fatemeh Mirjalili Mohammad Ali Sheikh-Mohseni Afsaneh Dehghani-Firouzabadi Alireza Khoshroo 《催化学报》2014,35(2):201-209
A chemically modified carbon paste electrode (CPE), consisting of 2,2''-[(1E)-(1,2-phenylenebis(azanylylidene)] bis(methanylylidene)]bis(benzene-1,4-diol) (PBD) and multiwalled carbon nanotubes (CNTs), was used to study the electrocatalytic oxidation of dopamine using cyclic voltammetry, chronoamperometry, and differential pulse voltammetry (DPV). First, the electrochemical behavior of the modified electrode was investigated in buffer solution. Then the diffusion coefficient, electrocatalytic rate constant, and electron-transfer coefficient for dopamine oxidation at the surface of the PBD-modified CNT paste electrode were determined using electrochemical approaches. It was found that under optimum conditions (pH = 7.0), the oxidation of dopamine at the surface of such an electrode occurred at about 200 mV, lower than that of an unmodified CPE. DPV of dopamine at the modified electrode exhibited two linear dynamic ranges, with a detection limit of 1.0 μmol/L. Finally, DPV was used successfully for the simultaneous determination of dopamine, uric acid, and folic acid at the modified electrode, and detection limits of 1.0, 1.2, and 2.7 μmol/L were obtained for dopamine, uric acid, and folic acid, respectively. This method was also used for the determination of dopamine in a pharmaceutical preparation using the standard addition method. 相似文献
84.
Somayeh Motavallizadeh Asal Fallah-Tafti Saeedeh Maleki Amir Nasrolahi Shirazi Mahboobeh Pordeli Maliheh Safavi Sussan Kabudanian Ardestani Shaaban Asd Rakesh Tiwari Donghoon Oh Abbas Shafiee Alireza Foroumadi Keykavous Parang Tahmineh Akbarzadeh 《Tetrahedron letters》2014
Several novel N-(9-oxo-9H-xanthen-4-yl)benzenesulfonamide derivatives were prepared as potential antiproliferative agents. The in vitro antiproliferative activity of the synthesized compounds was investigated against a panel of tumor cell lines including breast cancer cell lines (MDA-MB-231, T-47D) and neuroblastoma cell line (SK-N-MC) using MTT colorimetric assay. Etoposide, a well-known anticancer drug, was used as a positive standard drug. Among synthesized compounds, 4-methoxy-N-(9-oxo-9H-xanthen-4-yl)benzenesulfonamide (5i) showed the highest antiproliferative activity against MDA-MB-231, T-47D, and SK-N-MC cells. Furthermore, pentafluoro derivatives 5a and 6a exhibited higher antiproliferative activity than doxorubicin against human leukemia cell line (CCRF-CEM) and breast adenocarcinoma (MDA-MB-468) cells. Structure–activity relationship studies revealed that xanthone benzenesulfonamide hybrid compounds can be used for the development of new lead anticancer agents. 相似文献
85.
Niloofar Moheimanian Jahan Bakhsh Raoof Afsaneh Safavi Reza Ojani 《Journal of the Iranian Chemical Society》2014,11(4):1217-1222
A novel nitrite biosensor was constructed by simultaneous immobilization of hemoglobin (Hb) and a room temperature ionic liquid, octylpyridinium chloride ([OcPy][Cl]), on multi-walled carbon ionic liquid electrode (MWILE). The direct electron transfer of Hb showed a pair of redox peaks with a formal potential of ?0.187 V vs. Ag/AgCl in pH 5.0 acetate buffer solution. Nitrite (NO2 ?) catalysis on the modified electrode was investigated by cyclic voltammetry and amperometry. The biosensor exhibited a wide linear range for NO2 ? detection from 0.01 to 15 mM, with a detection limit (3σ) of 1.46 μM. MWILE provided an excellent matrix for protein immobilization and biosensor fabrication which could be used for the determination of NO2 ? with a low detection limit, fast response, long linearity, and excellent sensitivity. 相似文献
86.
Peyman Salehi Mohammad M. Khodaei Mohammad A. Zolfigol Afsaneh Keyvan 《Monatshefte für Chemie / Chemical Monthly》2002,133(10):1291-1295
Summary. Crossed aldol condensations of ketones with aromatic aldehydes are carried out efficiently in the presence of magnesium hydrogensulfate
under solvent-free conditions in good to excellent yield without the occurrence of any self-condensation. Similar reactions
in solution do not proceed satisfactorily.
Corresponding authors. E-mail: p-salehi@cc.sbu.ac.ir
Received September 20, 2001. Accepted (revised) January 16, 2002 相似文献
87.
Peyman Salehi Mohammad M. Khodaei Mohammad A. Zolfigol Afsaneh Keyvan 《Monatshefte für Chemie / Chemical Monthly》2002,27(11):1291-1295
Crossed aldol condensations of ketones with aromatic aldehydes are carried out efficiently in the presence of magnesium hydrogensulfate under solvent-free conditions in good to excellent yield without the occurrence of any self-condensation. Similar reactions in solution do not proceed satisfactorily. 相似文献
88.
89.
Safavi A Abdollahi H Maleki N Zeinali S 《Journal of colloid and interface science》2008,322(1):274-280
The interactions of an imidazolium based ionic liquid (IL), namely 1-dodecyl-3-methylimidazolium chloride [C12 mim][Cl] with two sulfonated anionic dyes, azocarmine G and methyl orange, are studied spectrophotometrically in both acidic and basic media. ILs (with some surface active character) can interact with the above dyes and cause considerable shifts in their spectra. These interactions are then compared with some surfactant-dye interactions. Evolving factor analysis (EFA) and multivariate curve resolution-alternating least squares (MCR-ALS) are used for complete resolution of the measured spectrophotometric data. The concentration and spectral profiles of all species were calculated without any assumption of the chemical models. The spectral variation of dye solutions as a function of IL concentrations below and above the critical aggregation concentration (CAC) is analyzed using MCR-ALS as a soft-modeling technique. The ion pair formation constants between ILs and dyes were calculated using the obtained concentration profiles. 相似文献
90.
The synthesis of some fluorescent 2,6‐dicyano‐3,5‐disubstituted anilines using cellulose sulfuric acid (Cellulose‐SA) as an environmentally benign catalyst in H2O is described. The one‐pot reaction of 1,3‐diketone and three equiv. of malononitrile was carried out in the presence of one equiv. of a secondary amine, Cellulose‐SA as catalyst, and H2O as solvent. The photophysical properties (λAbs., λFlu.) of the synthesized compounds in CH2Cl2, MeCN, and MeOH have been measured. The emission spectra of the new compounds in the solid state are also reported. 相似文献