Open Access Published by De Gruyter Open Access

Volume 10 Issue 2

April 2012

Issue of Open Chemistry

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Journal Overview

Open Access January 29, 2012

A review on the synthesis of TiO2 nanoparticles by solution route

Shipra Gupta, Manoj Tripathi

Page range: 279-294

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Abstract

TiO2 can be prepared in the form of powder, crystals, or thin films. Liquid-phase processing is one of the most convenient and utilized methods of synthesis. It has the advantage of allowing control over the stoichiometry, production of homogeneous materials, formation of complex shapes, and preparation of composite materials. However, there may be some disadvantages such as expensive precursors, long processing times, and the presence of carbon as an impurity. In comparison, the physical production techniques, although environment friendly, are limited by the size of the produced samples which is not sufficient for a large-scale production. The most commonly used solution routes in the synthesis of TiO2 are reviewed.

Open Access January 29, 2012

Synthesis of fluorescent long-chain thiols/disulfides as building-blocks for self-assembled monolayers preparation

Sushilkumar Jadhav

Page range: 295-299

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Abstract

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.

Open Access January 29, 2012

Mung bean response during immobilization of exchangeable aluminum in acidic soil

Monika Skwira, Agata Jakóbik-Kolon, Jerzy Ciba

Page range: 300-304

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Abstract

A soil incubation and shot-term plant growth experiment was conducted to study the effect of ferruginous mineral application on exchangeable Al immobilization. The mineral containing mainly siderite was mixed at various rates with A-horizon soil and incubated at 80% humidity for 45 days. Following the incubation, a short-term plant growth test was carried out using mung beans. The ferruginous mineral application into tested soil resulted in a reduction of the exchangeable aluminum concentration and soil acidity. An increase in root growth and stalk length, as well as a general improvement of plant condition was observed in the case of ferruginous mineral application. This observation was confirmed by chemical analysis of roots and stalks. The greatest amount of essential elements: calcium and magnesium and the lowest amount of aluminum were determined in green part of mung beans sown in the soil with addition of 2% ferruginous mineral.

Open Access January 29, 2012

Development of cephalexin-loaded poly(ethyl cyanoacrylate) colloidal nanospheres

Georgi Yordanov

Page range: 305-312

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Abstract

This article considers the preparation and physicochemical characterization of a novel colloidal formulation of the β-lactam antibiotic cephalexin, loaded in poly(ethyl cyanoacrylate) colloidal nanospheres. The drug was loaded by means of drug incorporation in the interior of poly(ethyl cyanoacrylate) particles during the polymerization of the respective monomer in aqueous medium. The obtained colloids were characterized by scanning electron microscopy, dynamic and electrophoretic light scattering, Fourier transform infrared and nuclear magnetic resonance spectroscopy. It was found that the drug loading efficiency depends on the initial concentration of monomer and cephalexin in the polymerization medium. The average size of cephalexin-loaded particles was around 400 nm and did not depend significantly on the concentrations of drug and monomer. Drug-loaded particles with drug content as high as 21% (w/w) were prepared. The drug release kinetics was studied in physiological phosphate-buffered saline. It was found that a biexponential model could describe well the experimental release kinetics.

Open Access January 29, 2012

Influence of acceptor functionality on charge transfer interactions in mixtures of poly(9-vinylcarbazole) with nitroaromatic compounds

Anca Grigoras, Virgil Barboiu

Page range: 313-319

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Abstract

Charge transfer interactions in mixtures of poly(9-vinylcarbazole) with three nitro compounds (4,4′dinitrodibenzyl, ethyl 3,5-dinitrobenzoate and 2,2′,4,4′-tetranitrodibenzyl) were examined. GPC shows an increase of apparent polymer weight average molecular weight (MW) in mixtures compared with pure PVK. Electron acceptors show upfield 1H-NMR shifts for all mixtures. The equilibrium association constants (k) calculated from the Benesi-Hildebrand equation are 0.511, 1.371, and 1.868 L mol−1 for PVK blends with DNDB, DNBE and TNDB, respectively. Shifts of (−NO2) stretch vibrations in mixtures support charge transfer complex formation between PVK chains and electron acceptors The ability to accept electrons decreases: TNDB>DNBE>DNDB.

Open Access January 29, 2012

Binuclear copper complexes with non-steroidal anti-inflammatory drugs as studied by electrospray ionization mass spectrometry

Kaja Kowcun, Magdalena Frańska, Rafał Frański

Page range: 320-326

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Abstract

The solutions containing one of the copper salts (CuCl2, Cu(ClO4)2, Cu(NO3)2, and CuSO4) and one of the non-steroidal anti-inflammatory drugs (NSAIDs, ibuprofen, ketoprofen or naproxen) were analyzed by electrospray ionization mass spectrometry. Three of the salts, namely CuCl2, Cu(ClO4)2 and Cu(NO3)2, yielded binuclear complexes of drug:metal stoichiometry 1:2. Existence of the complexes of such stoichiometry has not been earlier observed. For copper(II) chloride the complexes (ions of the type [M-HCOOH+Cu2Cl]+ and [M+Cu2Cl]+, M stands for the drug molecule) were formed in the gas phase. When copper(II) perchlorate or copper(II) nitrate was used, the observed binuclear copper complexes (ions of the type [M-H+Cu2(ClO4)2+CH3OH]+, [M-H+Cu2(ClO4)2]+ and [M-H+Cu2(NO3)2+CH3OH]+, [M-H+Cu2(NO3)2]+) were observed at low cone voltage, thus these complexes must have already existed in the solution analysed. Therefore, such complexes may also exist under physiological conditions.

Open Access January 29, 2012

The effect of manganese on the structural and surface properties of nanocrystalline cobalt catalyst for ammonia synthesis

Zofia Lendzion-Bieluń

Page range: 327-331

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Abstract

Based on the active surface model of the iron catalyst for ammonia synthesis, the assumptions which led to obtaining the cobalt catalyst for ammonia synthesis were described. The incorporation into the system small amounts of manganese, an element which binds oxygen stronger than cobalt, has influence the development of the catalyst’s specific surface area. The activity of manganese modified catalysts is higher than that of cobalt catalyst without manganese addition. The obtained catalysts were characterized with the following methods: ICP-OES, XRD, BET

Open Access January 29, 2012

The solubility of Ca(OH)2 in extremely concentrated NaOH solutions at 25°C

Attila Pallagi, Ágost Tasi, Attila Gácsi, Miklós Csáti, István Pálinkó, Gábor Peintler, Pál Sipos

Page range: 332-337

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Abstract

The solubility of Ca(OH)2 in aqueous NaOH solutions up to 12.50 M at 25°C has been determined. The solubility data obtained for NaOH concentrations lower than 3 M was compared with those published in the literature. The solubility of Ca(OH)2 steadily decreases with the increasing NaOH concentration. The solubility data obtained at a constant ionic strength (I = 1 M Na(Cl,OH)) enabled the determination of the conditional solubility product of Ca(OH)2(s) (lgLCa(OH)2 = − 4.10 ± 0.02). Formation of the hydroxo complex CaOH+(aq) was invoked to describe the variation of [Ca2+]T with [OH−]T. Its conditional stability constant was found to be lgKCaOH+ = 0.97 ± 0.02. The experimental protocol employed was proven to be suitable for accurate solubility determinations in rapidly equilibrating systems comprising of highly concentrated, alkaline solutions and containing analytes in the ppm range.

Open Access January 29, 2012

Thermodynamic dissociation constants of risedronate using spectrophotometric and potentiometric pH-titration

Milan Meloun, Zuzana Ferenčíková, Hana Málková, Tomáš Pekárek

Page range: 338-353

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Abstract

Risedronate inhibits bone resorption in diseases like osteoporosis, Paget’s disease, tumor bone diseases or the malfunction of phosphocalcium metabolism. The acid-base properties of risedronate in an aqueous solution have been studied in a pH range from 2 to 12 and can be described in terms of four dissociation steps: pK a,2, pK a,4, pK a,5 (related to the dissociation of POH groups) and pK a,3 related to the dissociation of protonated amino group NH3+. The mixed dissociation constants were determined at different ionic strengths I = 0.02 to 0.20 mol dm−3 KCl and of 25°C and 37°C using pH-spectrophotometric and pH-potentiometric titration methods. Determination of group parameters L 0, H T might lead to false estimates of common parameters p K a;therefore, the computational strategy employed is important. A comparison between the two programs ESAB and HYPERQUAD demonstrated that the ESAB program provides a better fit of potentiometric titration curve. The thermodynamic dissociation constants pK aT were estimated by a nonlinear regression of (pK a, I) data and a Debye-Hückel equation at 25°C and 37°C, pK a,2T = 2.37(1) and 2.44(1), pK a,3T = 6.29(3) and 6.26(1), pK a,4T = 7.48(1) and 7.46(2) and pK a,5T = 9.31(7) and 8.70(3) at 25°C and 37°C using pH-spectroscopic data and pK a,2T = 2.48(3) and 2.43(1), pK a,3T= 6.12(2) and 6.10(2), pK a,4T = 7.25(2) and 7.23(1) and pK a,5T = 12.04(5) and 11.81(2) at 25°C and 37°C. The ascertained estimates of three dissociation constants pK a,3, pK a,4, pK a,5 are in agreement with the predicted values obtained using PALLAS

Open Access January 29, 2012

The crystal structure of Ho4Ni11In20

Yuriy Tyvanchuk, Volodymyr Svitlyk, Yaroslav Kalychak

Page range: 354-359

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Abstract

The polycrystalline Ho4Ni11In20 was obtained by arc-melting of the elements. The subsequent high temperature procedure was used for single crystal growth. Crystal structure of the compound was investigated by X-ray single crystal method: U4Ni11Ga20 type, C 2/m, a = 22.4528(17), b = 4.2947(3), c = 16.5587(13) Å, β = 124.591(5)°, R1 = 0.0276, wR2 = 0.0493 for 1989 independent reflections with [I>2σ(I)]. The structure is composed of three-dimensional network from Ni and In atoms in which Ho atoms fill distorted pentagonal channels.

Open Access January 29, 2012

Synthesis of dibromo ketones by the reaction of the environmentally benign H2O2-HBr system with oximes

Alexander Terent’ev, Igor Krylov, Vera Vil’, Zhanna Pastukhova, Sergey Fastov, Gennady Nikishin

Page range: 360-367

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Abstract

It was found that oximes undergo deoximation in the presence of the H2O2aq-HBraq system to form ketones and bromo ketones. This reaction provided the basis for the synthesis of dibromo ketones in yields varying from 40% to 94%. This method is environmentally friendly, sustainable, and easy to perform. The results of this investigation extend the potential of the use of oximes for the protection of carbonyl group, thus offering the ability to perform not only conventional deoximation but also the subsequent bromination of ketones. The reaction is easily scaled up and dibromo ketones can be prepared in gram amounts.

Open Access January 29, 2012

Optimization study of the catalytic activity of DNAzymes based on telomeric G-quadruplexes

Joanna Kosman, Bernard Juskowiak

Page range: 368-372

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Abstract

Optimization studies of the procedure for peroxidase activity measurements with DNAzymes based on telomeric sequences and colorimetric indicator reactions are reported. Effect of metal cation, nature and concentration of surfactant, as well as thermal treatment of G-quadruplex sample are investigated. Nature of metal cation exhibited modest influence on the system performance. Great improvement of enzymatic activity of the telomeric quadruplexes in the presence of Brij 58 surfactant was observed. Further improvement of catalytic activity of the system based on human telomeric sequence was attained by applying a thermal treatment (heating/rapid cooling) procedure to prepare G-quadruplex/hemin complexes.

Open Access January 29, 2012

New 1H-1-alkyl-6-methyl-3-phenyl-7-phenylazo-pyrazolo[5,1-c][1,2,4]triazoles through regioselective alkylation of 1H-6-methyl-3-phenyl-7-phenylazopyrazolo[5,1-c][1,2,4]triazoles

Vasile-Nicolae Bercean, Valentin Badea, Călin Deleanu, Alina Nicolescu

Page range: 373-379

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Abstract

1H-1-Alkyl-6-methyl-3-phenyl-7-phenylazopyrazolo[5,1-c][1,2,4]triazoles (2aa-ad) were obtained by regioselective alkylation of 1H-6-methyl-3-phenyl-7-phenylazopyrazolo[5,1-c][1,2,4]triazoles (2a). 1H-1-Alkyl-6-methyl-3-phenyl-7-phenylazopyrazolo[5,1-c][1,2,4]triazoles 2aa and 2ab were also prepared by coupling phenyldiazonium chloride with 1H-1-alkyl-6-methyl-3-phenyl-pyrazolo[5,1-c][1,2,4]triazoles 1aa and 1ab. The new compounds were characterized by IR, UV-VIS, 1H-NMR, 13C-NMR, and 15N-NMR spectroscopy and their structures and actual tautomeric forms were established unequivocally.

Open Access January 29, 2012

Mathematical approach to investigation of synthesis processes at high temperatures

Mažvydas Mackevičius, Feliksas Ivanauskas, Aivaras Kareiva

Page range: 380-385

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Abstract

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.

Open Access January 29, 2012

Synthesis of novel 3-deoxy-3-C-triazolylmethyl-allose derivatives and evaluation of their biological activity

Jekaterina Rjabova, Vitālijs Rjabovs, Antonio Moreno Vargas, Elena Clavijo, Māris Turks

Page range: 386-394

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Abstract

Recently, monosaccharide-triazole conjugates have proved to possess a large variety of useful biological activities. This paper describes synthesis of a new series of 3-deoxy-3-C-triazolylmethyl-allose derivatives. These new compounds are obtained from acetonide-protected 3-deoxy-3-azidomethyl allose and commercial alkynes via Cu(I) catalyzed 1,3-dipolar cycloaddition. The obtained molecular scaffolds differ from those described earlier by the presence of a methylene linker (-CH2-) between the C(3) of allose and the triazole moiety. It was demonstrated that acetonide-protected monosaccharide, 3-deoxy-3-C-(4-phenyl-1H-1,2,3-triazol-1-yl)methyl-1,2:5,6-di-O-isopropylidene-α-d-allofuranose, inhibited α-L-fucosidase for 26% at 0.1 mM concentration, but a deprotected analog, 3-deoxy-3-C-(4-(4-tert-butylphenyl)-1H-1,2,3-triazol-1-yl)methyl-β-d-allofuranose, showed 15% inhibition of β-glucosidase at 1 mM concentration.

Open Access January 29, 2012

Theoretical investigation of the Anti-Parkinson drug rasagiline and its salts: conformations and infrared spectra

U. Başköse, Sevgi Bayarı, Semran Sağlam, Hacı Özışık

Page range: 395-406

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Abstract

The conformational analysis of rasagiline [N-propargyl-1(R)-aminoindan] was performed by the density functional theory (DFT) B3LYP method using the 6–31++G (d,p) basis set. A single point energy calculations based on the B3LYP optimized geometries were also performed at MP2/6-31++G (d, p) level. The vibrational frequencies of the most stable conformer of rasagiline was calculated at the B3LYP level and vibrational assignments were made for normal modes on the basis of scaled quantum mechanical force field (SQM) method. The influence of mesylate and ethanedisulfonate salts on the geometry of rasagiline free base and its normal modes are also discussed.

Open Access January 29, 2012

Using 2-D electrophoresis followed by nano HPLC in nuclear protein analysis of MCF-7 breast cancer cell line by MALDI-TOF/TOF

Soňa Tkáčiková, Ivan Talian, Marián Petrovič, Ján Sabo

Page range: 407-412

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Abstract

The biomarker identification is an important tool in early cancer detection. The MCF-7 breast cancer cell line was chosen as a model system. The nuclear proteins were extracted utilizing a commercially manufactured kit and separated on two dimensional (2-D) sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE). The first dimension was performed on isoelectric focusing strips with pH range 4–7. Afterwards the proteins were tryptic digested and identification was performed by matrix assisted laser desorption technique with time of flight mass analyzer (MALDI-TOF/TOF). For unambiguous identification proteins with too low concentration or spots contains protein mixture the nano high performance liquid chromatography (HPLC) was used. The 2-D gel electrophoresis (2-DGE) seems to be a good tool to separate large amount of proteins using relatively simple procedure and its hyphenation with HPLC can create the perfect analytical solution for proteome identification. About 150 nuclei protein spots were visualized and the most abundant of them were identified.

Open Access January 29, 2012

Erratum to: “Syntheses and characterisation of chloro(η3-allyl) dicarbonylmolybdenum(II) complexes of chiral and achiral ditertiaryphosphines”

Joe Jesu Raj, Devendra Pathak, Pramesh Kapoor

Page range: 413-413

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Abstract

The original version of the article was published in Cent. Eur. J. Chem. 10(1) (2012), pp 165–171. Unfortunately, the original version of this article contains mistakes in the affiliation section. Dr Devendra D. Pathak’s affiliation is Department of Applied Chemistry, Indian School of Mines, Dhanbad 826 004, India. Dr Pramesh N. Kapoor’s affiliation is Department of Chemistry, University of Delhi, Delhi 110 007, India.

About this journal

Open Chemistry is a peer-reviewed, open access journal that publishes original research, reviews, and communications in the fields of chemistry in an ongoing way. Our central goal is to provide a hub for researchers working across all subjects to present their discoveries, and to be a forum for the discussion of the important issues in the field.

There are no submission charges. In order to sustain the production of our fully-refereed open access journal, each article accepted for publication in Open Chemistry is subject to Article Processing Charges (APC).

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Advanced Nanomaterials for Energy, Environmental and Biological Applications
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Marine Environmental Sciences and significance of the multidiscplinary approaches for assessing pollutions, remedies, and predictions
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Energy conversion and energy storage reactions
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Recent Trends in Green Chemistry
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Therapeutic Potentials of Natural Compounds Targeting Malaria
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Advancements at the Nexus of Mathematics, Artificial Intelligence, and IoT in Medicinal Chemistry and Healthcare
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