共查询到20条相似文献,搜索用时 31 毫秒
1.
Jadwiga Jasińska Beata Krzyżyńska Mieczysław Kozłowski 《Central European Journal of Chemistry》2011,9(5):925-931
Activated carbons containing different surface functionalities have been investigated as catalysts in conversion reactions
of ethanol and methanol. These carbon materials were prepared from Polish brown coal by chemical activation with potassium
hydroxide and modified by the oxidation or reaction with ammonia or chlorine. The main process upon ethanol decomposition
was its dehydrogenation, while in the process of methanol decomposition only a few samples were catalytically active, and
the only product was dimethyl ether (a product of dehydration).
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2.
Mi?osz Mi?tkiewski Beata Powa?a Bartosz Staniszewski Maciej Kubicki W?odzimierz Urbaniak Cezary Pietraszuk 《Central European Journal of Chemistry》2011,9(4):728-736
Selected β-diketones bearing unsaturated derivatives have been demonstrated to undergo homo-metathesis and cross-metathesis with selected
olefins in the presence of Grubbs catalysts. The reactions led to respective homo- and cross-metathesis products mainly with
good yields and selectivities.
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3.
The oxidative catalytic degradation of the cationic dye methylene blue (MB) with NaOCl in aqueous solutions was studied using
individual and iron modified Ni- and Co-oxide systems as catalysts. The adsorption extent and the contribution of the uncatalyzed
oxidation on the overall degree of MB were determined. The results indicate that methylene blue—a representative of a class
of dyestuffs resistant to biodegradation—could be successfully decolorized and degraded using nickel and cobalt oxide catalysts
at room temperature. The highest catalytic activity manifests in the Co-oxide system which is consistent with the adsorption
data. The oxidative degradation reaction proceeds via first-order kinetics. Temperature has a relatively small effect on the
methylene blue degradation kinetics. The results obtained reveal that the catalysts investigated are suitable for oxidative
destruction of methytlene blue dye in wastewaters.
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4.
Sushilkumar A. Jadhav 《Central European Journal of Chemistry》2012,10(2):295-299
New symmetrical disulfides together with the corresponding thiols bearing fluorescent end-groups have been synthesized as
building-blocks for self-assembled monolayers (SAMs). The synthesis has been accomplished starting from aromatic nitrogen
heterocycles in three steps. The conversion of the tosylated intermediate into the final disulfide is accomplished by use
of sodium hydrogen sulfide (NaSH). Both products (thiols and disulfides) were isolated and characterized.
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5.
Ramin Ghorbani-Vaghei Seyedeh Mina Malaekehpour 《Central European Journal of Chemistry》2010,8(5):1086-1089
N,N,N,’N’-Tetrabromobenzene-1,3-disulfonamide [TBBDA] is found to be a reusable catalyst for efficient synthesis of various amidoalkyl
naphthols from β-naphthol, aromatic aldehydes and urea in good to high yields under solvent-free conditions.
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6.
Fluorescence spectroscopy and circular dichroism (CD) spectroscopy were used to investigate the interaction of coumarin-3-carboxylic
acid with human serum albumin (HSA) and bovine serum albumin (BSA) under physiological conditions in a buffer solution of
pH 7.4.
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7.
Santosh S. Katkar Pravinkumar H. Mohite Lakshman S. Gadekar Balasaheb R. Arbad Machhindra K. Lande 《Central European Journal of Chemistry》2010,8(2):320-325
A rapid and an efficient one-pot method for the synthesis of quinoxalines catalysed by ZnO-beta zeolite at room temperature
is described. This environmentally benign method provides several advantages over methods that are currently employed such
as a simple work-up, mild reaction conditions, good to excellent yields, and a process to recover and reuse the catalyst for
several cycles with consistent activity.
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8.
Lakshman S. Gadekar Shivshankar R. Mane Santosh S. Katkar Balasaheb R. Arbad Machhindra K. Lande 《Central European Journal of Chemistry》2009,7(3):550-554
Natural scolecite has been found as an effective catalyst for the one-pot synthesis of 2,4,5-triarylimidazole derivatives
via a three component reaction using benzil or benzoin, aldehydes and ammonium acetate. This method provides several advantages
such as being environmentally benign, reusable, possessing high yields with increased variations of the substituents in the
product and preparative simplicity.
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9.
Bingcheng Yang Feifang Zhang Xinmiao Liang 《Central European Journal of Chemistry》2012,10(3):472-479
This review summarizes the development of capillary ion chromatography (CIC) over approximately the last 5 years. It mainly
focuses on the technologic aspects of several key components associated with CIC, including micropump, microscale electrodialytic
eluent generator, microscale suppressor and the detector.
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10.
Vincenzo Siano Ilaria D’Auria Fabia Grisi Chiara Costabile Pasquale Longo 《Central European Journal of Chemistry》2011,9(4):605-609
Grubbs II generation catalyst (3), bearing a fluorinated imidazolinium ligand, was investigated in cross metathesis (CM), ring closing metathesis (RCM) and
ring opening polymerization metathesis (ROMP) for a variety of substrates. Kinetic studies showed reduced stability of the
catalyst in methylene chloride following the first 15 minutes of reaction preventing a higher efficiency despite the very
high activity. Beneficial solvent effects on the catalyst stability were observed by performing RCM in C6F6.
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11.
This article describes the simple hydrodehalogenation of halogenated anilines and their derivatives by the action of Raney
aluminium-nickel alloy in aqueous alkaline solution at room temperature. The reaction course was monitored by means of 1H
nuclear magnetic resonance (NMR) spectroscopy and GC-MS spectra.
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12.
Joanna Kurczewska Grzegorz Schroeder Urszula Narkiewicz 《Central European Journal of Chemistry》2010,8(2):341-346
The synthesis of metal (Fe, Co, Ni)-encapsulated carbon nanomaterials coated with cyclam-bonded silica has been described.
The organic layer was identified by Fourier transform infrared spectroscopy and elemental analysis. The functionalized magnetic
nanomaterials were employed to extract the divalent cations: copper, calcium, cobalt, manganese and nickel from aqueous solutions.
Their adsorption capacities were studied by the batch procedure. The concentration of cations extracted was determined by
inductively coupled plasma mass spectrometry. Influence of different parameters viz. pH, amount of the compound studied, contact
time, on the cation extraction was investigated. Under optimum conditions copper extraction was significantly more efficient
when compared with other coexisting ions.
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13.
M. Teresa Barros Ana I. Mouquinho Krasimira T. Petrova Mara D. Saavedra João C. Sotomayor 《Central European Journal of Chemistry》2011,9(4):557-566
It has been reported that the length of the molecular chain and the rigidity of molecules influence the structure of the polymer
network in PDLC films and hence the electro-optical properties of the composites. Herein, a series of new aromatic monomeric
monomethacrylates, bismethacrylates and monovinylbenzene derivatives with a mesogenic core were successfully synthesized under
microwave irradiation. The microwave assisted synthesis resulted in decreased reaction times, reduced solvent requirement,
increased operational simplicity, and in most cases, improved yields and selectivity.
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14.
A palladium complex with an aminophosphine ligand has been prepared and investigated as a catalyst precursor in Suzuki coupling
reactions in toluene. Nanoparticles composed of elemental palladium have been isolated from the reaction media and analyzed
using transmission electroscopic microscope (TEM), which shows the essential catalysts palladium nanoparticles to have a size
of ca. 3.0 nm.
dedicate to the 60th birthday of Prof. Dr. Yuan Kou 相似文献
15.
Mažvydas Mackevičius Feliksas Ivanauskas Aivaras Kareiva 《Central European Journal of Chemistry》2012,10(2):380-385
In our work, we present a method for estimation of the diffusion and reaction rates of synthesis at high temperatures using
limited information from laboratory experiments, such as synthesis time and dimensions of reactants. Synthesis by sol-gel
and solid-state reactions is considered. The inverse modeling problem is solved for one- and two-dimensional models. Explicit
formulas for the diffusion coefficient and reaction rate as functions of temperature are obtained. The activation energies
are calculated, and the lower bounds of diffusion and reaction rates are estimated, thus obtaining conditions for occurrence
of synthesis.
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16.
17.
Sandip A. Sadaphal Kiran F. Shelke Swapnil S. Sonar Murlidhar S. Shingare 《Central European Journal of Chemistry》2008,6(4):622-626
1-benzyl-3-methyl imidazolium hydrogen sulphate [bnmim][HSO4] was found to be an effective catalyst for the condensation reaction of indoles and derivatives with benzaldehydes in microwave
irradiation with lower reaction time and higher yields to give bis(indolyl) methanes.
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18.
Cory C. Pye 《Central European Journal of Chemistry》2011,9(4):567-571
A geometry and SCF convergence study of Hartree-Fock calculations using the 6-31G* basis set is carried out on the set of
all possible diatomic molecules formed from atoms with Z≤36. The utility of Hartree-Fock calculations using the smaller STO-3G
basis set to improve the convergence behavior is demonstrated.
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19.
Irena Baranowska Sylwia Magiera Jacek Baranowski 《Central European Journal of Chemistry》2011,9(6):972-981
The aim of this paper is to optimize and validate a high performance liquid chromatography (HPLC) method for separation and
quantification of five isoflavones. A statistical central composite design was used to separate all peaks. These multivariate
procedures were efficient in determining the optimal separation condition using resolution, capacity factor, asymmetry and
number of theoretical plates.
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20.
Melinda Fekete Mercedesz Töröncsi Lajos Novak 《Central European Journal of Chemistry》2008,6(1):33-37
Palladium-catalyzed amination reactions of quinoline triflate and the effect of a Pd catalyst, its ligands, solvents, bases,
and temperature were studied. This method facilitated an easier pathway for the preparation of aminoquinoline derivatives
as potential precursors of new serotoninerg agents.
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