共查询到20条相似文献,搜索用时 65 毫秒
1.
Francis E. Appoh Marcy J. Manning Teri J. Gullon Margaret A. Hansen Emily C. Bevans Krista D. M. Hogan Courtney S. Turner Christopher M. Vogels Andreas Decken Stephen A. Westcott 《Central European Journal of Chemistry》2008,6(3):359-364
The Ugi reaction with formylphenylboronic acid derivatives as the carbonyl component proceeds to give the corresponding boron-containing
dipeptide derivatives (Ugi products) in good yields.
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2.
Study of flocculation with PONILIT GT-2 anionic polyelectrolyte applied into a chemical wastewater treatment 总被引:1,自引:0,他引:1
Carmen Zaharia Rodica Diaconescu Mioara Surpăţeanu 《Central European Journal of Chemistry》2007,5(1):239-256
This paper discusses the applications of synthetic PONILIT GT-2 anionic polyelectrolyte in conjuction with ferric sulfate
in a chemical wastewater treatment viz. wastewater from ceramics manufacturing. Synthetic wastewaters with different colloid
concentrations were prepared and the coagulation-flocculation process followed by sedimentation and/or filtration was studied.
Variables associated with the chemical wastewater composition, mixing time, and the coagulant and flocculant dose are considered
in order to appreciate the process efficiency in terms of turbidity, chemical oxygen demand (COD), and color removal. The
degrees are higher for turbidity and color (> 80 %) removal respectively, and, satisfactory for COD (< 50 %). An empirical
model was elaborated by a third order rotatable design 23 type, considering ferric sulfate dose, polyelectrolyte dose, and mixing time as independent variables, while the turbidity
and color removal efficiencies were chosen as optimization criteria. The empirical model was found adequate for the chemical
wastewater treatment. Also, an analysis of the model was performed to find the optimal operating conditions, in order to apply
this process for an efficient chemical wastewater treatment using ferric sulfate as coagulation agent and PONILIT GT-2 anionic
polyelectrolyte as flocculation agent. The optimal values correspond to a ferric ions concentration of 6.093 mg/L, a polyelectrolyte
dose of 0.651 mg/L, and a mixing time of 24.024 minutes for turbidity removal (95.869 %), respectively, and, to a ferric ions
concentration of 6.01 mg/L, a polyelectrolyte dose of 0.69 mg/L, and a mixing time of 26 minutes for color removal (98.741
%).
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3.
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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4.
Olaf Kühl 《Central European Journal of Chemistry》2008,6(3):365-372
N-Heterocyclic germylenes are known to exist in two structurally different forms, the planar Meller germylenes and the monoimino
germylenes that feature an envelope structure. This essay reviews recent reports dealing with radical and cationic Meller
type germylenes featuring the monoimino germylene structure, discusses their transformations and relationships, and asks the
question whether indeed N-heterocyclic germylenes can be turned into Lewis acids.
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5.
Noora Kuuloja Tuula Kylmälä Youjun Xu Robert Franzén 《Central European Journal of Chemistry》2008,6(3):390-392
Xenbucin 1, an analgesic drug, was synthesized in 4 steps using two different routes. The biaryl fragment could successfully be produced
via a Pd/C catalysed Suzuki coupling in water using sodium tetraphenylborate as a phenylation reagent. Overall yields of the
routes were 36% and 59%, respectively.
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6.
A one-pot multi-component reaction is developed for the efficient synthesis of 4,5-dibenzylidene octahydroacridines in high
yields. The reaction is performed by the tandem reaction of three molar equivalent aromatic aldehydes with two molar equivalent
4-alkylcyclohexanone in the system of NH4OAc/HOAc under microwave irradiation.
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7.
Raluca Turdean Elena Bogdan Anamaria Terec Anca Petran Laurian Vlase Ioan Turcu Ion Grosu 《Central European Journal of Chemistry》2009,7(1):111-117
The synthesis of new 3,7-dibromophenothiazine derivatives bearing bromoalkyl, mercaptoalkyl and alkylthioacetate groups on
the N atom at position 10 is reported. The Suzuki coupling reaction of one of these derivatives via the bromine atoms at positions
3 and 7 with bromothiophene derivatives is also discussed.
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8.
9.
D. A. Svechkarev G. V. Karpushina L. L. Lukatskaya A. O. Doroshenko 《Central European Journal of Chemistry》2008,6(3):443-449
Three 2-(benzimidazol-2-yl)-3-hydroxychromone derivatives were synthesized. Their spectroscopic and fluorescent properties,
due to excited state intramolecular proton transfer (ESIPT) from OH to carbonyl, were studied. Theoretical possibility of
an alternative intramolecular H-bonding and experimental evidence for such behavior are discussed.
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10.
Tsonko Kolev Bojidarka B. Koleva Michael Spiteller 《Central European Journal of Chemistry》2008,6(3):393-399
The applications of linear-polarized IR-spectroscopy to oriented colloid suspensions in a nematic host are demonstrated with
croconic and rhodizonic acids. The experimental IR vibrational assignments of the solid-state of both neutral compounds are
presented. Assignments are supported by theoretical quantum chemical calculations and vibrational analysis at the DFT level
of theoretical approximation with the 6-311++G** basis set.
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11.
The kinetics of the C-S coupling of arylmagnesium bromides with phenyl tosylate has been studied in THF: toluene at 90°C.
The reaction is first order in Grignard reagent and first order in phenyl tosylate. Kinetic data, Hammett relationship and
activation parameters are consistent with a nucleophilic addition mechanism involving rate determining attack of carbanion
to sulfonyl group followed by a fast phenoxide group leaving.
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12.
Mariusz Walkowiak Daniel Waszak Błażej Gierczyk Grzegorz Schroeder 《Central European Journal of Chemistry》2008,6(4):600-606
Impact of silicon tripodand-type electrolyte additives and graphite pre-treatment agents on the electrochemical intercalation
of lithium cations into graphite was investigated. Addition of Si-tripodand-type silanes to propylene carbonate-based electrolytes
was found to suppress detrimental solvent co-intercalation and graphite exfoliation. Similar effects were observed for graphite
pre-treated with the reported silane agents. It was observed that the presented supramolecular additives allow for the formation
of effective passive layers on graphite during first charging, and thus can be considered as novel low-cost film-forming components
for rechargeable lithium batteries.
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13.
Soufiane El Houssame Hafid Anane Larbi El Firdoussi Abdellah Karim 《Central European Journal of Chemistry》2008,6(3):470-476
The palladium(0) catalyzed amination of allylic acetates and carbonates derivatives from terpenic olefins was carried out
under mild conditions. The reaction offers a very good method for the preparation of allylic amines and thus to provide a
useful entry to new functionalized terpenic olefin products. The mechanism involving a formation of p-allyl-palladium intermediate
complex is in good agreement with the results obtained with the optically active substrates, as well as via an analysis of
the observed regio-and stereoselectivity.
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14.
Capillary electrophoresis (CE) is an attractive technique in separation science because of its high separation performance,
short analysis time and low cost. Electrochemical detection (EC) is a powerful tool for CE because of its high sensitivity.
In this review, developments of CE-EC from 2008 to August, 2011 are reviewed. We choose papers of innovative and novel results
to demonstrate the newest and most important progress in CE-EC.
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15.
Rūta Araminaitė Rasa Garjonytė Albertas Malinauskas 《Central European Journal of Chemistry》2008,6(2):175-179
Kinetic study on the decomposition of Prussian Blue electrocatalytic layer during electrochemical reduction of hydrogen peroxide
has been studied in relation to biosensor application of this electrocatalyst. The decomposition has been shown to proceed
as a nearly exponential decay process and the corresponding first-order rate coefficients were determined. It has been shown
that the decomposition proceeds about 10 times faster in pH 7.3 buffer solution as compared to pH 5.5 buffer. A linear dependence
of the decomposition rate on the concentration of hydrogen peroxide has been found.
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16.
A novel hydroxyamino phosphane was synthesised through the reaction of 2-imidazolidinone with ClPPh2 and subsequently reaction
of the resulting bisphosphino derivative with the Grignard reagent BrMgC5H11. The interaction of the pentyl substituent with one of the two phosphino groups and the structure in solution is shown by
multinuclear NMR-spectroscopy..
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17.
A colour change of doped YAB crystals and microcrystalline powders takes place upon illumination with different white light
sources. This paper presents extensive experimental data on the new materials Ho,Nd:YAB; Ho,Cr:YAB, Nd,Cr:YAB and Ho,Nd,Cr:YAB,
resulting in a chart providing the observed crystal colours and chromaticity differences of the materials under illumination
with seven different types of white light sources. The microcrystalline powders could be used as coatings in order to produce
a special colour changing effect. Furthermore, the colour table presented enables the observer to discriminate the investigated
light sources at one glance.
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18.
Dominique R. Duguay Matthew T. Zamora Johanna M. Blacquiere Francis E. Appoh Christopher M. Vogels Susan L. Wheaton Felix J. Baerlocher Andreas Decken Stephen A. Westcott 《Central European Journal of Chemistry》2008,6(4):562-568
The addition of formylphenylboronic acid derivatives to thiourea and ethyl acetoacetate proceeds in the presence of an additional
Lewis acid catalyst to give the corresponding 3,4-dihydropyrimidin-2(1H)-(thio)ones (Biginelli products) in moderate yield.
Compounds were tested for antifungal activity against pure cultures of Aspergillus niger, Aspergillus flavus, Candida albicans and Saccharomyces cerevisiae but, unfortunately, none showed any appreciable activity.
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19.
Chiral aminosulfonamides containing imidazolium group were used as ligands for the ruthenium(II)-catalyzed asymmetric transfer
hydrogenation of prochiral ketones in ionic liquid, affording good to excellent conversions and enantiomeric excesses. The
catalytic system could be easily recovered and reused several times.
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20.
In this report, we described the synthesis and characterization of a variety of diaminotriarylmethane derivatives with dimethylamino
functional groups. These compounds were synthesized by the tandem regio-selective electrophilic aromatic substitution reaction
of N,N-dimethylaniline with aryl aldehydes to form the corresponding diaminotriarylmethane compounds. In our strategy, Bi(NO3)3 was used as a catalyst under solvent free conditions to afford the desired products in good to excellent yields.
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