共查询到20条相似文献,搜索用时 62 毫秒
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Emil Ioan Muresan Spiridon Oprea Theodor Malutan Mihai Vata 《Central European Journal of Chemistry》2007,5(3):715-726
The esterification reaction of palmitic acid with epichlorohydrin catalyzed by an anionic macroporous resin was studied. Purolite
A-500 resin proved to be a very effective catalyst in the synthesis of 3-chloro-2-hydroxypropyl palmitate. The effects of
certain parameters such as speed of agitation, catalyst particle size, catalyst loading, temperature, initial molar ratio
between reactants on the rate of reaction were studied. It was found that the overall rate is intrinsically kinetically controlled.
The structure of synthesized ester was confirmed by FTIR and 1H NMR analyses.
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3.
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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4.
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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5.
Li-Wen Xu Ming-Song Yang Jian-Xiong Jiang Hua-Yu Qiu Guo-Qiao Lai 《Central European Journal of Chemistry》2007,5(4):1073-1083
Ionic liquid-functionalized mesoporous materials exhibited high catalytic activity in versatile organic reactions, such as
cycloaddition of carbon dioxide (CO2) with epoxide, aza-Michael addition of amines to α, β-unsaturated carbonyl compounds, and the Biginelli reaction of aldehyde, ethyl acetoacetate and urea. Recycling of the catalyst
in these reactions could be carried out and the catalyst used at least five times without significant loss in activity.
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6.
Adina Raducan Alexandra Olteanu Mihaela Puiu Dumitru Oancea 《Central European Journal of Chemistry》2008,6(1):89-92
The kinetics of the reaction between malachite green (MG) and sodium hydroxide (MG fading) was studied using a spectrophotometric
method in the presence of two cationic surfactants, cetyl-benzyl-dimethyl-ammonium chloride (CBDAC) and hexadecyl-trimethylammonium
bromide (HTAB) and one anionic surfactant, sodium dodecyl sulphate (SDS) at concentrations below and above critical micellar
concentrations. The cationic surfactants have a catalytic effect, while the anionic surfactant has an inhibitory effect on
the reaction. A kinetic model describing the influence of surfactant on reaction rate was developed. The results are discussed
on the basis of electrostatic and hydrophobic interactions between the kinetic micelles and malachite green.
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7.
The intermolecular non-covalent interactions in aminonitromethylbenzenes namely 2-methyl-4-nitroaniline, 4-methyl-3-nitroaniline,
2-methyl-6-nitroaniline, 4-amino-2,6-dinitrotoluene, 2-methyl-5-nitroaniline, 4-methyl-2-nitroaniline, 2,3-dimethyl-6-nitroaniline,
4,5-dimethyl-2-nitroaniline and 2-methyl-3,5-dinitroaniline were studied by quantum mechanical calculations at RHF/311++G(3df,2p)
and B3LYP/311++G(3df,2p) level of theory. The calculations prove that solely geometrical study of hydrogen bonding can be
very misleading because not all short distances (classified as hydrogen bonds on the basis of interaction geometry) are bonding
in character. For studied compounds interaction energy ranges from 0.23 kcal mol−1 to 5.59 kcal mol−1. The creation of intermolecular hydrogen bonds leads to charge redistribution in donors and acceptors. The Natural Bonding
Orbitals analysis shows that hydrogen bonds are created by transfer of electron density from the lone pair orbitals of the
H-bond acceptor to the antibonding molecular orbitals of the H-bond donor and Rydberg orbitals of the hydrogen atom. The stacking
interactions are the interactions of delocalized molecular π-orbitals of the one molecule with delocalized antibonding molecular
π-orbitals and the antibonding molecular σ-orbital created between the carbon atoms of the second aromatic ring and vice versa.
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8.
Graphene multilayers have been prepared by mechanical method based on milling graphite in high efficient attritor mill. The
results showed that the best dispersion media is ethanol, and 10 hours of intensive milling proved to be the most efficient
way to separate the graphite layers as it was shown by scanning electron microscopy and X-ray diffraction measurements.
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9.
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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10.
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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11.
Nitin A. Mirgane Sandip B. Kotwal Anil V. Karnik 《Central European Journal of Chemistry》2010,8(2):356-360
Ionic liquids (IL) are gaining importance as green solvents. Imidazolium ionic liquid [bmim]+[Cl]−, an environmentally benign solvent, was found to promote the Diels-Alder reaction between anthrone and maleimides at room
temperature with excellent yields. The ionic liquid played a dual role as solvent and catalyst.
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12.
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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13.
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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14.
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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15.
The triplet excited state properties and photosensitization mechanisms of indigo were investigated based on density functional
theory calculations. The solvent effects on the photosensitization mechanisms of indigo have also been considered. The thermodynamic
feasibility of the possible 1O2 and O2·−-photogeneration pathways by triplet excited state indigo in different solvents was explored, in order to gain some deeper
insights into the photosensitization characters of the dye.
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16.
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.
相似文献
17.
Vivek Srivastava 《Central European Journal of Chemistry》2010,8(2):269-272
Sulphonimide based organocatalyst was used to catalyze the aldol reaction in ionic liquid media. On the basis of yield and
selectivity the ionic liquid mediated system was found superior in comparison with organic solvents. The added advantages
of this ionic liquid mediated organocatalysis are easy recovery of product and the recyclability of the organocatalyst.
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18.
Ksenija R. Kumrić Tatjana M. Trtić-Petrović Ljubiša M. Ignjatović Jožef J. Čomor 《Central European Journal of Chemistry》2008,6(1):65-69
Lutetium has been determined by differential pulse anodic stripping voltammetry in an acidic solution containing Zn-EDTA.
Lutetium (III) ions liberated zinc (II), which was preconcentrated on a hanging mercury drop electrode and stripped anodically,
resulting in peak current linearly dependent on lutetium (III) concentration. Less than 0.4 ng mL−1 lutetium could be detected after a 2 min deposition.
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19.
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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20.
In the present study, Quantitative Structure-Activity Relationship (QSAR) modeling has been carried out for lipid peroxidation
(LPO)-inhibition potential of a set of 27 flavonoids, using structural and topological parameters. For the development of
models, three methods were used: (1) stepwise regression, (2) factor analysis followed by multiple linear regressions (FA-MLR)
and (3) partial least squares (PLS) analysis. The best equation was obtained from stepwise regression analysis (Q2 = 0.626) considering the leave-oneout prediction statistics.
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