Physical chemistry
Mohsen Oftadeh; Masood Fereidoonnezhad; Mina Aliyan; Fariba Aliyan
Abstract
A set of Xanthohumol derivatives were selected and molecular docking studies of these compounds on thioredoxin reductase were conducted. Based on new structural patterns using in silico-screening study, new potent lead compounds were designed. The results due to validated docking protocols ...
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A set of Xanthohumol derivatives were selected and molecular docking studies of these compounds on thioredoxin reductase were conducted. Based on new structural patterns using in silico-screening study, new potent lead compounds were designed. The results due to validated docking protocols lead to find that Thr58, Gly57, Gly21, Asp334, Glu163, Ala130, IIe332, Val44 and Gly132 are the main amino acids in the active site cavity in charge of essential interactions with thioredoxin reductase.
Analytical chemistry
Hamid Reza Zare-Mehrjardi
Volume 6, Issue 3, pp. 218-324, Serial No. 20 , July 2018, , Pages 300-311
Abstract
In this paper, the carbon paste electrode (CPE) is modified using an ionic liquid (1-Butyl-3-methylimidazolium tetrafluoroborate, [BMIM]BF4) and the cis-dioxo-bis[3-methoxy-2,2-dimethylpropanediamine] molybdenum(VI) complex (cis-[Mo(O)2L]). In order to study of the electrochemical behavior of ascorbic ...
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In this paper, the carbon paste electrode (CPE) is modified using an ionic liquid (1-Butyl-3-methylimidazolium tetrafluoroborate, [BMIM]BF4) and the cis-dioxo-bis[3-methoxy-2,2-dimethylpropanediamine] molybdenum(VI) complex (cis-[Mo(O)2L]). In order to study of the electrochemical behavior of ascorbic acid (AA) and dopamine (DA) at the surface of the prepared CPEs, the differential pulse and cyclic voltammetric methods (DPV and CV) were used. The percent of the [BMIM]BF4 in the matrix of the modified CPE is optimized, and then the effect of the pH of the buffered solution on the electrode response and the resolution between the anodic peaks of AA and DA is studied by CV and DPV. These results reveal that by application of the modified CPE a peak resolution about 325mV is obtained for AA and DA and the linear range for AA and DA in buffered solutions of pH 5.0 is acquired in the range from 5.0×10−7 to 1.0×10−3 M. The respective limits of detection (S/N = 3) were 1×10−7 M and 2×10−7 M for DA and AA, respectively. Surface regeneration and the very easy preparation of the modified CPE together with the very good peak resolution and sub-micromolar detection limits designate the prepared CPE in this work appropriate for simultaneous voltammetric determination of DA and AA.
Physical chemistry
Mohammad Zakarianezhad; Motahare Shool
Volume 5, Issue 3, pp. 237-363, Serial No. 16 , July 2017, , Pages 301-307
Abstract
In the recent work, the reaction mechanism between triphenylphosphine 1, dialkyl acetylenedicarboxylates 2 in the presence of NH-acid, such as 5-aminoindazole 3 were investigated theoretically. Quantum mechanical studies were performed for evaluation of potential energy surfaces of all structures participated ...
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In the recent work, the reaction mechanism between triphenylphosphine 1, dialkyl acetylenedicarboxylates 2 in the presence of NH-acid, such as 5-aminoindazole 3 were investigated theoretically. Quantum mechanical studies were performed for evaluation of potential energy surfaces of all structures participated in the reaction mechanism both in gas phase and in dichloromethane. The first step of all reactions was recognized as a rate-determining step in the reaction mechanism. All the possible structures partipated on the reaction coordinate were well predicted. Quantum mechanical calculations were clarified how the ylides exist in solution as a mixture of two geometrical isomers (Z- and E-) as a minor or major forms.
Organic chemistry
Mohammad Piltan
Volume 3, Issue 4, pp. 283-387, Serial No. 9 , October 2015, , Pages 367-373
Abstract
An efficient synthesis of trialkyl (E)-3-(3-Oxo-2-3,4-dihydro-2-(1H)-quinoxalinylidene)-prop-1-ene-1,2,3-tricarboxylate derivatives via a simple three-component reaction between benzene-1,2-diamines with dialkyl acetylenedicarboxylates in the presence of K2CO3-PEG catalytic system at 100 oC was reported. ...
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An efficient synthesis of trialkyl (E)-3-(3-Oxo-2-3,4-dihydro-2-(1H)-quinoxalinylidene)-prop-1-ene-1,2,3-tricarboxylate derivatives via a simple three-component reaction between benzene-1,2-diamines with dialkyl acetylenedicarboxylates in the presence of K2CO3-PEG catalytic system at 100 oC was reported. The desired products were obtained in excellent yields (88-92%). Various benzene-1,2-diamines, and dialkyl acetylendicarboxylate were used in the traditional method. Quinolines are major classes of heterocyclic compounds, which have attracted considerable attention from chemists for their large broad biological activities and amazing physical properties. Furthermore, the synthesis of quinoxalines and their derivatives has received much attention from organic and medicinal chemists. As part of our current studies on the development of new routes to synthesize quinoxaline systems. The corresponding quinoxalines are useful building blocks for the construction of complex quinoxaline derivatives
Organic chemistry
Radineh Motamedi; Ghasem Rezanejade Bardajee; Somaye Shakeri
Volume 5, Issue 4, pp. 364-493, Serial No. 17 , October 2017, , Pages 442-448
Abstract
Some chromeno[4′,3′-b]pyrano[6,5-b]quinoline derivatives were synthesized by condensation of 2-amino-4-aryl-3-cyano-5-oxo-4H, 5H -pyrano-[3,2-c] chromenes and 1,3-cyclohexanedione in an environmentally benign and efficient method by Cu(II)-Schiff base/SBA-15 as an environmentally friendly ...
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Some chromeno[4′,3′-b]pyrano[6,5-b]quinoline derivatives were synthesized by condensation of 2-amino-4-aryl-3-cyano-5-oxo-4H, 5H -pyrano-[3,2-c] chromenes and 1,3-cyclohexanedione in an environmentally benign and efficient method by Cu(II)-Schiff base/SBA-15 as an environmentally friendly heterogeneous and recyclable catalyst under solvent-free conditions in high yields and rates. These kinds of catalysts are built from mesoporous silica SBA-15 which was covalently anchored with Cu(II) Schiff base complex. The shorter reaction times, good yields, simple work-up procedure and environmentally friendly conditions are the main advantages of this method compared to the last one. The product was identified by its 1H NMR, mass and IR spectra, which were compared to those reported previously.
Inorganic chemistry
Reza Golbedaghi; Alirza Salehi
Volume 6, Issue 1, pp. 1-108, Serial No. 18 , January 2018, , Pages 78-86
Abstract
In this paper we report the synthesis and characterization of two new binuclear Cd(II) macrocyclic Schiff base complexes [CdL23pydfp(NO3)], (1), and [CdL33pydfp(NO3)], (2). [1+1] cyclocondensation of L23py = N-(2-pyridylmethyl)-N-(3-aminpropyl)-1,3-diaminoethane and L33py = N-(3-pyridylmethyl)-N-(3-aminpropyl)-1,3-diaminopropane ...
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In this paper we report the synthesis and characterization of two new binuclear Cd(II) macrocyclic Schiff base complexes [CdL23pydfp(NO3)], (1), and [CdL33pydfp(NO3)], (2). [1+1] cyclocondensation of L23py = N-(2-pyridylmethyl)-N-(3-aminpropyl)-1,3-diaminoethane and L33py = N-(3-pyridylmethyl)-N-(3-aminpropyl)-1,3-diaminopropane and 2,6-diformyl-4-methylphenol, dfp, in the presence of Cd(NO3)2.4H2O in equimolar ratios gave two new macrocylclic complexes. Resulting complexes were characterized by NMR, IR, mass spectroscopy and elemental analysis. Spectroscopy studying results show in spite the nitrogen and oxygen atoms of macrocyclic ligand with N4O donor set, one nitrate molecule (with two donor oxygen atoms) is coordinated to the Cd(II) center in each complex. So, the cadmium center is seven coordinated.
Inorganic chemistry
Mahboube Eslami Moghadam; Abdolghafar Abolhosseini Shahrnoy; Taghi Karimi; Satar Alyar
Volume 4, Issue 1, pp. 1-132, Serial No. 10 , January 2016, , Pages 115-122
Abstract
Fullerene chemistry is nowadays a well-established field of both theoretical and experimental investigations. This study considers the symmetry of small fullerenes cage C24 and C28. Using PM3 program for C24 and C28 fullerenes, Oh and Td symmetry were confirmed, respectively. ...
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Fullerene chemistry is nowadays a well-established field of both theoretical and experimental investigations. This study considers the symmetry of small fullerenes cage C24 and C28. Using PM3 program for C24 and C28 fullerenes, Oh and Td symmetry were confirmed, respectively. The mentioned algorithm to compute the automorphism group of these fullerenes with connectivity and geometry of their symmetry point groups was improved. Here, we computed the symmetry of these small fullerenes by simple method such as Groups, Algorithms and Programming (GAP) system. It was proved that there are groups of order 48 which has 10 conjugacy classes for C24 and 24 which has 5 conjugacy classes for C28, respectively. Also, the conjugacy classes and character table were computed.
Organic chemistry
Masoomeh Abdoli; Maryam Hajibabaiee
Volume 3, Issue 2, pp. 72-147, Serial No. 7 , April 2015, , Pages 143-147
Abstract
Some 3, 5-diacyl or 3,5-diester 1,4-dihydropyridines were oxidized to the corresponding pyridine derivatives using hydrogen peroxide in aqueous ethanol in the presence of potassium bromide and acetic acid as the catalysts. The reaction was carried out in ethanol and products were isolated in high to ...
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Some 3, 5-diacyl or 3,5-diester 1,4-dihydropyridines were oxidized to the corresponding pyridine derivatives using hydrogen peroxide in aqueous ethanol in the presence of potassium bromide and acetic acid as the catalysts. The reaction was carried out in ethanol and products were isolated in high to excellent yields. However, oxidation of 3,5-diacetyl 1,4-dihydropyridines is slower than 3,5-diester 1,4-dihydropyridines under the same condition. Furhermore, the reaction is facilitated by electron releasing groups on 4-substituent of dihydropyridine ring. The cheapness of reagent, high yielding, easy workup and mild condition makes this method a useful addition to the available method in organic synthesis. In addition, employment of clean oxidant H2O2 together with nontoxic solvent ethanol makes it friendly to the environment.
Organic chemistry
Hamed Ramezanalizadeh
Volume 6, Issue 2, pp. 109-217, Serial No. 19 , April 2018, , Pages 192-208
Abstract
In this work a novel heterojunction catalyst have been synthesized and employed as a highly efficient catalyst for one-pot synthesis of substituted imidazoles. Analytical methods including Fourier transform infrared (FT-IR), diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), Energy- dispersive ...
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In this work a novel heterojunction catalyst have been synthesized and employed as a highly efficient catalyst for one-pot synthesis of substituted imidazoles. Analytical methods including Fourier transform infrared (FT-IR), diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), Energy- dispersive X-ray spectroscopy (EDX), Scanning electron microscopy (SEM) and Vibrating Sample Magnometer (VSM) were used for the catalyst characterization. Moreover, the catalyst was also recovered and reused five times without remarkable decrease in its catalytic activity. Compared to the classical methodologies, this method illustrated significant advantages including low loading of the catalyst, short reaction times, high to excellent yields, easy separation and purification of the products.
Organic chemistry
Amira A. Ghoneim; Mohamed G. Assy; Enaiat K. Mohamed; Islam Ragab
Volume 5, Issue 2, pp. 121-236, Serial No. 15 , April 2017, , Pages 195-206
Abstract
Acylisothiocyanate (1) was allowed to react with benzylidene malononitrile producing oxazine derivative (2). Also, compound (1) was reacted with sodium azide followed by refluxing with sodium ethoxide affording thiazinotetrazole derivative (4). The reaction of acetylacetone with compound (1) gave pyridine ...
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Acylisothiocyanate (1) was allowed to react with benzylidene malononitrile producing oxazine derivative (2). Also, compound (1) was reacted with sodium azide followed by refluxing with sodium ethoxide affording thiazinotetrazole derivative (4). The reaction of acetylacetone with compound (1) gave pyridine derivative (5) by intramolecular cycloaddition while it was reacted with N-methyl aniline affording thiazine derivative (7). In addition, it was reacted with cyanoacetamide producing mercaptopyrimidine derivative (9). Finally, compound (1) was refluxed with phenylhydrazine, urea, guanidinum carbonate and anthranilic acid in the presence of dry acetone affording triazole derivative (11), N-substituted pyrimidine (15), compound (18) and thiopyrimidine derivative (19) respectively. The structures of the new compounds were confirmed on the basis of elemental and spectral data. Some of the synthesized compounds were screened as anticancer.
Organic chemistry
Batol Zakerinasab; Mohammad Ali Nasseri; Hassan Hassani
Volume 4, Issue 2, pp. 133-235, Serial No. 11 , April 2016, , Pages 214-225
Abstract
Cellulose bonded N-propyl diethylene tetra sulfamic acid (CBPDETSA) was successfully applied as a green and recyclable acidic catalyst for the synthesis of tetrahydrobenzo [a] xanthene-11-one as an important class of potentially bioactive compounds. The products are obtained by the coupling of 2-naphtol ...
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Cellulose bonded N-propyl diethylene tetra sulfamic acid (CBPDETSA) was successfully applied as a green and recyclable acidic catalyst for the synthesis of tetrahydrobenzo [a] xanthene-11-one as an important class of potentially bioactive compounds. The products are obtained by the coupling of 2-naphtol , cyclohexadione and aldehyde derivatives in good to high yields (70- 92%) under solvent-free conditions. The reactivity of different aromatic aldehydes was influenced by the nature and position of the substituents on the aromatic ring. The benzaldehyde derivatives having an electron-withdrawing substituent were highly reactive and gave the products in excellent yields. Also, the catalyst could be recovered by filtration and subjected to a second reaction process. The results show that the yield of product after five runs was only slightly reduced.
Organic chemistry
Shahryar Abbasi; Mahmoud Roushani; Hadi Noorizadeh
Abstract
In this work, we developed a method based on ultrasound-assisted emulsification microextraction (USAEME) for the determination of zinc and copper by flame atomic absorption spectrometry (FAAS). The method is based on the use of the organic solvent carbon tetrachloride (CCl4) as an extraction solvent. ...
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In this work, we developed a method based on ultrasound-assisted emulsification microextraction (USAEME) for the determination of zinc and copper by flame atomic absorption spectrometry (FAAS). The method is based on the use of the organic solvent carbon tetrachloride (CCl4) as an extraction solvent. In order to obtain a high enrichment factor, the effect of different parameters affecting the complex formation and extraction conditions (such as the type and volume of the extraction solvent, pH, the chelating agent amount, extraction time, extraction temperature and ionic strength) were tested. Under optimum conditions, the eight replicates mixture of the 100 ngmL-1 and 50 ngmL-1 for Zn(II) and Cu(II) ions, gave a mean absorbance of 0.055 and 0.061, with a relative standard deviation (RSD) of ±%3.2 and 2.9, respectively. The equations for the lines were A = 0.4921C + 0.0027 (R = 0.9998) and A = 1.0701C + 0.0032 (R = 0.9997), respectively. The limit of detection for Zn (II) and Cu(II) ions were 1.06 and 1.4 ngL−1, respectively. The calibration graph was linear in the range of 3.0–2000.0 ngmL−1 and 2.0-850.0 ngmL−1 for Zn and Cu respectively. In the proposed procedure, enhancement factors were 9.51 and 6.25 for Zn and Cu, respectively. This proposed method was successfully applied in the analysis of four real environmental water samples and good spiked recoveries over the range of 98.4–103.0% were obtained. This is a first research used USAEME for simultaneous determination Zn and Cu in water.
Organic chemistry
Abbas Amini Manesh; Ardeshir Khazaei; Maedeh Gohari; Mahdieh Chegeni; Shahnaz Saednia
Volume 5, Issue 3, pp. 237-363, Serial No. 16 , July 2017, , Pages 308-314
Abstract
Methoxymethylation of a variety of alcohols was performed using formaldehyde dimethyl acetal in the presence of 1,3-dichloro-5,5-dimethyl hydantoin [DCDMH] and Poly N,N′-dibromo-N-ethyl naphthyl-2,7-disulfonamide [PBNS] as catalysts at room temperature and under solvent-free conditions. Our experiments ...
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Methoxymethylation of a variety of alcohols was performed using formaldehyde dimethyl acetal in the presence of 1,3-dichloro-5,5-dimethyl hydantoin [DCDMH] and Poly N,N′-dibromo-N-ethyl naphthyl-2,7-disulfonamide [PBNS] as catalysts at room temperature and under solvent-free conditions. Our experiments show that primary and secondary alcohols can be smoothly converted into the corresponding MOM-ethers in excellent yields. The methoxymethyl ethers (MOM-ethers) were obtained with good to excellent yields. 1,3-Dichloro-5,5-dimethyl hydantoin [DCDMH] and Poly N,N′-dibromo-N-ethyl naphthyl-2,7-disulfonamide [PBNS] effectively catalyzed the methoxymethylation of alcohols with dimethoxymethane at ambient temperature. The notable advantages of this method are mild reaction conditions, high yields, cheapness, safety and eco-friendliness, and recyclability of the catalysts.
Nanochemistry
Maryam Movahedi; Akram Hosseinian; Nasrin Nazempour; Mohadeseh Rahimi; Hossein Salavati
Volume 3, Issue 4, pp. 283-387, Serial No. 9 , October 2015, , Pages 374-387
Abstract
In the present work, ZnO/Bi2O3, SnO2/Bi2O3/Bi2O4 mixed oxide, Bi2O3 rod-like and SnO2 nanoparticle have been synthesized. The obtained samples were characterized by field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD). The optical properties of samples were evaluated by UV-Vis ...
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In the present work, ZnO/Bi2O3, SnO2/Bi2O3/Bi2O4 mixed oxide, Bi2O3 rod-like and SnO2 nanoparticle have been synthesized. The obtained samples were characterized by field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD). The optical properties of samples were evaluated by UV-Vis spectrophotometer. The photocatalytic activity of samples was evaluated by decolorization of methylene blue (M.B.) solution. The Present work indicates the improving or hampering effect of Bi2O3 on the photocatalytic activity of ZnO/Bi2O3. The results show that the photocatalytic performance of ZnO/Bi2O3 which is higher than that of Bi2O3, SnO2, and SnO2/Bi2O3/Bi2O4 is related to the presence of the zinc oxide semiconductor. Furthermore, results indicated that the photoactivity of the SnO2/Bi2O3 system was not improved. The present work affirms the importanat position of energy levels and also the separation of photogenerated electron/hole pairs on the efficient photocatalytic performance.
Organic chemistry
Ali Ramazani; Masoome Sheikhi Sheikhi; Ali Souldozi; Sang Woo Joo; Hooriye Yahyaei
Volume 5, Issue 4, pp. 364-493, Serial No. 17 , October 2017, , Pages 449-470
Abstract
Dimethyl (z)-2-[(2-methyl-5-oxo-1-cyclopentyl)oxy]-2-butenedioate has been synthesized using one-pot three component reaction between N-isocyaniminotriphenylphosphorane (Ph3PNNC), 3-methylcyclopentene-1,2-dione and dimethyl acetylenedicarboxylate. Also, optimized geometry and nuclear magnetic resonance ...
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Dimethyl (z)-2-[(2-methyl-5-oxo-1-cyclopentyl)oxy]-2-butenedioate has been synthesized using one-pot three component reaction between N-isocyaniminotriphenylphosphorane (Ph3PNNC), 3-methylcyclopentene-1,2-dione and dimethyl acetylenedicarboxylate. Also, optimized geometry and nuclear magnetic resonance ( NMR ) of the title compound are evaluated using HF and B3LYP methods and 6-311+G(d) basis set. Moreover, the 1H and 13C NMR chemical shift values of the molecule are calculated and compared with experimental results. Frontier molecular orbitals (FMOs), total density of states (DOS), electronic properties, natural charges, NMR parameters and NBO analysis for product were calculated by theoretical calculations. Finally, molecular electrostatic potential (MEP) surface is obtained for understanding the active regions of molecule.
Organic chemistry
Mohammad Reza Poor Heravi; Naheed Morsalie
Volume 6, Issue 1, pp. 1-108, Serial No. 18 , January 2018, , Pages 87-96
Abstract
Highly substituted 1,4-dihydropyrano[2,3-c]pyrazole derivatives were synthesized by four-component reaction of aromatic aldehydes, malononitrile, ethyl acetoacetate and various phenylhydrazine, using nickel ferrite as a recyclable nanocatalyst by a grinding method under solvent-free and thermal conditions. ...
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Highly substituted 1,4-dihydropyrano[2,3-c]pyrazole derivatives were synthesized by four-component reaction of aromatic aldehydes, malononitrile, ethyl acetoacetate and various phenylhydrazine, using nickel ferrite as a recyclable nanocatalyst by a grinding method under solvent-free and thermal conditions. The reaction has the advantages of good yields, less pollution, ease of separation of the desired products, and of being environment friendly. A possible mechanism for this reaction was proposed. Highly substituted 1,4-dihydropyrano[2,3-c]pyrazole derivatives were synthesized by four-component reaction of aromatic aldehydes, malononitrile, ethyl acetoacetate and various phenylhydrazine, using nickel ferrite as a recyclable nanocatalyst by a grinding method under solvent-free and thermal conditions. The reaction has the advantages of good yields, less pollution, ease of separation of the desired products, and of being environment friendly. A possible mechanism for this reaction was proposed.
Physical chemistry
Esmaeil Vessally; Ali Jafari; Elaheh Ahmadi
Volume 4, Issue 1, pp. 1-132, Serial No. 10 , January 2016, , Pages 123-132
Abstract
In this work, the optimization calculations were carried out on quetiapine hemifumarat, 4, and its analogues, 1-5. These calculations were carried out using the B3LYP/6-31G(d) level of theory. The DFT calculations clarified a boat structure for dibenzothiazepine moiety of the molecule which piperazine ...
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In this work, the optimization calculations were carried out on quetiapine hemifumarat, 4, and its analogues, 1-5. These calculations were carried out using the B3LYP/6-31G(d) level of theory. The DFT calculations clarified a boat structure for dibenzothiazepine moiety of the molecule which piperazine moiety has a chair conformation. Thermal energies (E), enthalpies (H), and free energies (G) of quetiapine and its analogues, 1-5 were calculated at the B3LYP/6-31G(d) level. The chemical hardness (η), chemical potential (μ), dipole moment (D), electrophilicity (ω) and the maximum amount of electronic charge, ΔNmax, were determined. Some molecular properties for quantitative structure activity relationships (QSAR) were investigated.
Analytical chemistry
Ahmadreza Amraei; Ali Niazi; Mohammad Alimoradi
Volume 5, Issue 2, pp. 121-236, Serial No. 15 , April 2017, , Pages 207-216
Abstract
Naphthol isomers were simultaneously and spectrophotometrically determined in wastewater, using a model based on net analyte signal (NAS). The calibration method used is a variation of the original hybrid linear analysis method as proposed by Goicoechea and Olivieri (HLA/GO). Owing to spectral interferences, ...
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Naphthol isomers were simultaneously and spectrophotometrically determined in wastewater, using a model based on net analyte signal (NAS). The calibration method used is a variation of the original hybrid linear analysis method as proposed by Goicoechea and Olivieri (HLA/GO). Owing to spectral interferences, the simultaneous determination of mixtures of naphthol isomers, using a spectrophotometric method, is difficult. A rapid and powerful method was used for wavelength selection in the modeling step, based on the minimization of the error indicator (EI), which was estimated as a function of the moving spectral region. The calculation of the net analytical signal using a modified HLA/GO method allows us to determine several figures of merit, as selectivity, sensitivity, analytical sensitivity and limit of detection of the proposed multivariate calibration. The limit of detection (LOD) for 1 and 2-naphthol, were 0.04 and 0.06 (µg/mL) respectively. The proposed model was tested in the analysis of wastewater samples, without previous sample preparation steps, obtaining recovery values between 98 and 104.00%, for 1-naphthol and between 97.00 and 103.00%, for 2-naphthol.
Physical chemistry
Ahmad Razavizadeh; Fahimeh Alirezapoor
Volume 6, Issue 2, pp. 109-217, Serial No. 19 , April 2018, , Pages 209-217
Abstract
In the present work, a modified equation of state has been presented for the calculation of volumetric properties of supercritical fluids. The equation of state is van der Waals basis with temperature and density-dependent parameters. This equation of state has been applied for predicting the volumetric ...
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In the present work, a modified equation of state has been presented for the calculation of volumetric properties of supercritical fluids. The equation of state is van der Waals basis with temperature and density-dependent parameters. This equation of state has been applied for predicting the volumetric properties of fluids. The densities of fluids were calculated from the new equation of state at different temperatures and pressures in the supercritical region. The predicted densities have been compared with those obtained from the experiment, over a broad range of pressure. It is found that the new equation of state yields excellent results in comparison with 1894 experimental data points with overall average absolute deviation percent (AAD %) of 0.98% in density for the pure studied compound. The studied fluids are: CH4, C2H6, C3H8, C4H10, C5H12, C6H14, C7H16, C8H18, C10H22, C12H26, C2H4, C6H6, C6H12, C7H8, O2, N2 and CO2.
Organic chemistry
Bagher Mohammadi; Maryam Rahmani
Volume 4, Issue 2, pp. 133-235, Serial No. 11 , April 2016, , Pages 226-235
Abstract
This work described a simple and efficient synthesis of dialkyl 3-(alkylamino)-1-aryl-1H-pyrazole-4,5-dicarboxylates via a three component reaction between arylhydrazine, alkylisocyanid and dialkylacetylenedicarboxylates in the presence of phenylisocyanate and α-Fe2O3 nanoparticles. Eco friendly, ...
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This work described a simple and efficient synthesis of dialkyl 3-(alkylamino)-1-aryl-1H-pyrazole-4,5-dicarboxylates via a three component reaction between arylhydrazine, alkylisocyanid and dialkylacetylenedicarboxylates in the presence of phenylisocyanate and α-Fe2O3 nanoparticles. Eco friendly, solvent-free conditions, excellent yields, and short reaction times, inexpensive and readily available catalysts are the main advantages of this method. In this work, phenylisocyanate and α-Fe2O3 nanoparticles used as a potent mixed catalyst for promoting the reaction and taking it in a special way to obtain the titled compounds in good to excellent yields. This reaction was not carried out without any of the components of this mixed catalyst. It means that for performance this reaction both of the mixed catalyst components is required.
Analytical chemistry
Parveen Rajjak Shaikh; Isak Rajjak Shaikh; Arjun Bapurao Bhosle
Volume 5, Issue 3, pp. 237-363, Serial No. 16 , July 2017, , Pages 315-337
Abstract
The physico-chemical properties of water and sediments therein were analyzed for assessing the suitability of Siddheshwar dam (India) waters for irrigation purpose. The physical parameters include total dissolved solids and electrical conductivity. The chemical parameters studied include pH, free carbon ...
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The physico-chemical properties of water and sediments therein were analyzed for assessing the suitability of Siddheshwar dam (India) waters for irrigation purpose. The physical parameters include total dissolved solids and electrical conductivity. The chemical parameters studied include pH, free carbon dioxide, total hardness, calcium hardness, magnesium hardness, phenolphthalein alkalinity, total alkalinity, biochemical oxygen demand and salinity. The present research was undertaken to monitor the irrigational suitability of this water body over the period of June 2009 to May 2010 by Sodium Absorption Ration (SAR), Magnesium Ratio (MR), Residual Sodium Carbonate (RSC), Soluble Sodium Percentage (SSP), Residual Sodium Bicarbonate (RSBC), Kelly’s Ratio (KR) and Permeability Index (PI) parameters. The UV-Spectrophotometer determined the concentrations of heavy metals such as iron, zinc, chromium and manganese. The sediments’ physico-chemical characteristics like temperature, conductivity, pH, % carbon, organic matter and phosphate have been detected by using standard methods. It is observed that the sediments are in a complex milieu with the overlying water in the aquatic ecosystem and they affect water chemistry and get affected by it. The water quality is found good and it is therefore safe for irrigation.
Organic chemistry
Jamal Davarpanah; Afzal Zafarpour; Behrooz Tayebi
Volume 5, Issue 4, pp. 364-493, Serial No. 17 , October 2017, , Pages 471-483
Abstract
In the present research, silica bonded n-propyl-1,3,5-triazine-2,4,6-triamine (SPTT) was synthesized by direct incorporation of chloropropyl groups through co-condensation of tetraethyl orthosilicate (TEOS) and 3-chloropropyl trimethoxysilane (CPTMS) and subsequent grafting the melamine onto the propyl ...
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In the present research, silica bonded n-propyl-1,3,5-triazine-2,4,6-triamine (SPTT) was synthesized by direct incorporation of chloropropyl groups through co-condensation of tetraethyl orthosilicate (TEOS) and 3-chloropropyl trimethoxysilane (CPTMS) and subsequent grafting the melamine onto the propyl groups via simple nucleophilic substitution reaction. The catalyst has been characterized by fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). The catalytic activity of catalyst was probed through synthesis of arylmethylenemalononitrile and pyran annulated heterocyclic compounds.The catalytic activity of catalyst was probed through synthesis of arylmethylenemalononitrile and pyran annulated heterocyclic compounds.The catalytic activity of catalyst was probed through synthesis of arylmethylenemalononitrile and pyran annulated heterocyclic compounds.
Organic chemistry
Hojat Veisi; Abbas Maleki; Yasaman Farokhzad
Volume 5, Issue 2, pp. 121-236, Serial No. 15 , April 2017, , Pages 217-226
Abstract
An electroorganic reaction for the synthesis of 7-amino-2, 4-dioxo-5-phenyl-2,3,4,5-tetrahydro-1H-pyrano[2, 3-d] pyrimidine-6-carbonitrile and ethyl-7-amino-2, 4-dioxo-5-phenyl-2,3,4,5-tetrahydro-1H-pyrano[2, 3-d] pyrimidine-6-carboxylate derivatives are described, using an electrogenerated base of the ...
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An electroorganic reaction for the synthesis of 7-amino-2, 4-dioxo-5-phenyl-2,3,4,5-tetrahydro-1H-pyrano[2, 3-d] pyrimidine-6-carbonitrile and ethyl-7-amino-2, 4-dioxo-5-phenyl-2,3,4,5-tetrahydro-1H-pyrano[2, 3-d] pyrimidine-6-carboxylate derivatives are described, using an electrogenerated base of the anion of malonitrile or ethylcyanoacetate. This one-pot, three-component condensation of an aromatic aldehyde, barbituric acid and malonitrile or ethylcyanoacetate takes place in ethanol in an undivided cell in the presence of tetrabutylammonium perchlorate as an electrolyte under mild conditions. This method has the advantages of high yields, wide application and employs an environmentally benign procedure.An electroorganic reaction for the synthesis of 7-amino-2, 4-dioxo-5-phenyl-2,3,4,5-tetrahydro-1H-pyrano[2, 3-d] pyrimidine-6-carbonitrile and ethyl-7-amino-2, 4-dioxo-5-phenyl-2,3,4,5-tetrahydro-1H-pyrano[2, 3-d] pyrimidine-6-carboxylate derivatives are described, using an electrogenerated base of the anion of malonitrile or ethylcyanoacetate. This one-pot, three-component condensation of an aromatic aldehyde, barbituric acid and malonitrile or ethylcyanoacetate takes place in ethanol in an undivided cell in the presence of tetrabutylammonium perchlorate as an electrolyte under mild conditions. This method has the advantages of high yields, wide application and employs an environmentally benign procedure.
Physical chemistry
Hajar Soltaninejad; Zahra Madadi; Tayebe Bagheri Lotfabad; Atefeh Pirani; Negissa Ebadipour
Volume 4, Issue 3, pp. 236-358, Serial No. 12 , July 2016, , Pages 236-244
Abstract
Acanthophyllum laxiusculum is one of the most widely distributed species of the genus in Iran that flourishes in steppe and mountainous regions of the country. In the present study, water-soluble content of A. laxiusculum roots was extracted by boiling water and further successively purified partially ...
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Acanthophyllum laxiusculum is one of the most widely distributed species of the genus in Iran that flourishes in steppe and mountainous regions of the country. In the present study, water-soluble content of A. laxiusculum roots was extracted by boiling water and further successively purified partially by a defined solvent system. Surface tension measurements revealed the ability of plant extract to decrease the surface tension of water from 72 to 38mN/m with a critical micelle concentration (CMC) of 87.3 mg/l. The partially purified natural extract (PPNE) exhibited 65% emulsification activity (E24) on kerosene. A combination of UV–VIS spectroscopy and Fourier transform infrared spectroscopy (FTIR) demonstrated the presence of saponin compounds in PPNE. Moreover, thermostability of PPNE was evaluated by thermal gravimetric analysis (TG) and differential thermal analysis (DTA). TG-DTG analysis showed a complex three-stage thermal degradation mechanism and this conclusion was also supported by the DTA spectrum.
Organic chemistry
Radineh Motamedi; Sara Sobhani; Farshid Barani
Volume 5, Issue 3, pp. 237-363, Serial No. 16 , July 2017, , Pages 338-344
Abstract
Some Chromeno[4,3-b]quinoline derivatives were synthesized in a tricomponents one-pot reaction of 1,3-cyclohexadione arylaldehydes and 4-aminocoumarin under Microwave irradiation in the solventless system by using a heteropolyacid catalyst ,H3[PW12O40] in 80-95% yields and high rates. The shorter reaction ...
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Some Chromeno[4,3-b]quinoline derivatives were synthesized in a tricomponents one-pot reaction of 1,3-cyclohexadione arylaldehydes and 4-aminocoumarin under Microwave irradiation in the solventless system by using a heteropolyacid catalyst ,H3[PW12O40] in 80-95% yields and high rates. The shorter reaction times, one-pot, good yields, simple work-up procedure and environmentally friendly conditions are the main advantages of this method compared to the two step method. Heteropolyacid is separated by filtration and the products were purified by flash column chromatography. The reactions were monitored by TLC and subsequent work-up afforded a single compound by TLC in each case. The product was identified by its 1H NMR, mass and IR spectra, which were compared to those reported previously.