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.
Physical chemistry
Ashraf M Ashmawy; Maher I Nessim; Doaa I Osman; El Sayed M Elnaggar
Abstract
Four liquid crystal compounds of the form, 2-Sec-butyl-4-[(4-x-phenyl) diazenyl) phenyl-4-(octadecyloxy] benzoate symbolized as I18a, I18b, I18c and I18d were prepared in which the substituent (X) was taken CH3O-, CH3-, Br- and -NO2 respectively. Characterization of prepared compounds is done using FT-IR, ...
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Four liquid crystal compounds of the form, 2-Sec-butyl-4-[(4-x-phenyl) diazenyl) phenyl-4-(octadecyloxy] benzoate symbolized as I18a, I18b, I18c and I18d were prepared in which the substituent (X) was taken CH3O-, CH3-, Br- and -NO2 respectively. Characterization of prepared compounds is done using FT-IR, 1H-NMR, Mass Spectroscopy and Elemental Analysis.. Their mesophase behavior was investigated by Differential Scanning Calorimetry (DSC). Their antioxidant efficiency for Egyptian lubricating base oil was tested. The oxidation processes was monitored using the change in the Total Acid Number (TAN). The obtained results showed that, the efficiency of these compounds was ranked as follows I18d > I18c > I18b > I18a.
Physical chemistry
Mahdi Rezaei Sameti; Fateme Ataeifar
Volume 6, Issue 3, pp. 218-324, Serial No. 20 , July 2018, , Pages 280-292
Abstract
In this research, the effects of HCN adsorption on the surface of the pristine, Ge, P, and GeP doped boron nitride nanotube (BNNTs) are investigated by using density function theory at the B3LYP/6–31G(d, p) level of theory. At the first step, we consider different configurations for adsorbing HCN ...
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In this research, the effects of HCN adsorption on the surface of the pristine, Ge, P, and GeP doped boron nitride nanotube (BNNTs) are investigated by using density function theory at the B3LYP/6–31G(d, p) level of theory. At the first step, we consider different configurations for adsorbing HCN molecule on the surface of BNNTs. The optimized models are used to calculate the structural, electrical, NQR parameters and quantum descriptors such as global hardness, global softness, electrophilicity, gap energy, Fermi level energy, electronic chemical potential, and electronegativity of BNNTs/HCN complex. Inspection of results demonstrates that with doping Ge impurity the sensivity of BNNTs for adsorbing HCN molecule increase significantly from original values. The adsorption of HCN molecule on the surface of Ge-doped is more stable and favourable than other those models. With adsorbing of HCN gas and doping of Ge and GeP the NQR, quantum molecular descriptors and molecular orbital energies of the nanotube alter significantly from original state. On the other hand the electrophilicity index of E model is more than those other models.
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.
Physical chemistry
Alireza Amini khouzani; Nasrin Sohrabi; Nahid Rasouli; Mahboube Eslami Moghadam
Volume 6, Issue 1, pp. 1-108, Serial No. 18 , January 2018, , Pages 30-38
Abstract
In this study, a nickel (II) complex with 1,10-phenanthroline based ligand, [Ni(FIP)2](OAC)2 (1) with FIP = 2-(Furan-2-yl)-1H-Imidazole[4,5-f][1,10] phenanthroline as ligand was synthesized and characterized by spectroscopic methods and elemental analysis. The interaction of [Ni(FIP)2](OAC)2 (1) with ...
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In this study, a nickel (II) complex with 1,10-phenanthroline based ligand, [Ni(FIP)2](OAC)2 (1) with FIP = 2-(Furan-2-yl)-1H-Imidazole[4,5-f][1,10] phenanthroline as ligand was synthesized and characterized by spectroscopic methods and elemental analysis. The interaction of [Ni(FIP)2](OAC)2 (1) with calf-thymus DNA (ct-DNA) was studied by UV-vis absorption, fluorescence spectroscopies and viscosity measurements in 20 mM Tris/HCl buffer solution, pH 7.0 at 25 °C. The complex (1) interacts with ct-DNA with an intrinsic binding constant of 1.11 ×105 M-1. Furthermore, the thermodynamic studies suggested that the interaction processes were endothermic disfavored (ΔH >0) and entropy favored (ΔS >0). The viscosity studies showed no considerable increasing changes in the viscosity of ct-DNA with increasing of the complex (1) concentration. Therefore, the [Ni(FIP)2](OAC)2 complex bind to ct-DNA via hydrophobic interaction as the main forces acting during the binding processes and the mode of binding is groove binding which was illustrated by hyperchromism in the UV-vis absorption band of [Ni(FIP)2](OAC)2 (1) with addition of ct-DNA and the decreasing of ethidium bromide (EB)-ct-DNA complex fluorescence in the presence of different concentrations of [Ni(FIP)2](OAC)2 complex and the unchanged viscosity of ct-DNA.
Physical chemistry
Venugopal Rajendran; Varathan Selvaraj; Pachaiyappan Abimannan
Volume 6, Issue 1, pp. 1-108, Serial No. 18 , January 2018, , Pages 55-61
Abstract
The present work describes, the reaction between disodium salt of 1,3-dihydroxybenzene (in situ formation) and propargyl bromide was carried out in a solid-liquid biphasic phase transfer catalytic system at 50°C. Higher selectivity of the bis-derivative (1,3-bis(prop-2-ynyloxy)benzene) was obtained ...
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The present work describes, the reaction between disodium salt of 1,3-dihydroxybenzene (in situ formation) and propargyl bromide was carried out in a solid-liquid biphasic phase transfer catalytic system at 50°C. Higher selectivity of the bis-derivative (1,3-bis(prop-2-ynyloxy)benzene) was obtained under solid-liquid PTC condion. The conversion of propargyl bromide of more than 99% was achieved in the presence of tetra-n-butylammonium bromide (TBAB) as catalyst. From the experimental evidence there is no mono-dervative observed. Experiments were conducted to increase the conversion of propargyl bromide such as, stirring speed, various PTCs, temperature, various solvents and amount of TBAB loading. All the experiments were conducted to obey pseudo-first order rate law. Apparent activation energy was also determined from the Arrhenius plot.
Physical chemistry
Fatemeh Elmi; Nasser Hadipour
Volume 5, Issue 4, pp. 364-493, Serial No. 17 , October 2017, , Pages 372-380
Abstract
A fragment of Histidine rich protein II (HRP II 215-236) was investigated by 14N and 17O electric field gradient, EFG, tensor calculations using DFT. This study is intended to explore the differences between 310-helix and α-helix of HRPII both in the gas phase and in solution. To achieve the aims, ...
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A fragment of Histidine rich protein II (HRP II 215-236) was investigated by 14N and 17O electric field gradient, EFG, tensor calculations using DFT. This study is intended to explore the differences between 310-helix and α-helix of HRPII both in the gas phase and in solution. To achieve the aims, the 17O and 14N NQR parameters of a fragment of HRPII (215-236) for both structures are calculated. Due to the side chain arrangements of the 310-helix, this conformation contains several hydrogen bonding contacts in comparison to the α-helix form. The resultant 14N and 17O s of peptide bonds of HRPII are affected by these contacts. Both in the gas phase and in solution, the differences in 14N s of backbone are within the uncertainties identical between two conformers but not for NH groups of backbone that the related amino acids participate in intramolecular hydrogen bond formation with side chain. In this case, the differences in 14N of backbone are avg.= 0.36 in gas phase and avg.= 0.43MHz in solution. However, differences in 17O parameters of the backbone C=O are distinguishable between two conformers, regardless of in gas phase and in solution, with and without influencing of the intramolecular hydrogen bond. These differences reveal how hydrogen bond interactions affect EFG tensors at the sites of oxygen and nitrogen nuclei.
Physical chemistry
Venugopal Rajendran; Varathan Selvaraj; Kuppusamy Harikumar
Volume 5, Issue 4, pp. 364-493, Serial No. 17 , October 2017, , Pages 381-396
Abstract
A new multi-site phase-transfer catalyst (MPTC), viz., N,N’-dioctyl-4,4’-bipyridium dibromide containing bi-site was prepared and proved by FT-IR, 1H NMR, 13C NMR, mass and elemental analysis. The enhancement of C-N+ peak intensity at 1179 cm−1 noticed in FT-IR, the agreement of m/z ...
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A new multi-site phase-transfer catalyst (MPTC), viz., N,N’-dioctyl-4,4’-bipyridium dibromide containing bi-site was prepared and proved by FT-IR, 1H NMR, 13C NMR, mass and elemental analysis. The enhancement of C-N+ peak intensity at 1179 cm−1 noticed in FT-IR, the agreement of m/z values, viz., 542.43 bi-site respectively with their theoretical values and the percentage of C, H, N elements noticed in elemental analysis has strongly supported the presence of tri-site MPTC catalysts. Further, the presence of number of active-sites in the catalyst was again confirmed by determining their pseudo-first order rate constant for dichlorocarbene addition to 1,3-bis(allyloxy)-5-methylbenzene in the presence of ultrasonic irradiation/mechanical stirring. The comparative study reveals that the kapp determined with the combination of ultrasound and mechanical stirring has shown more activity than with their individual effect. Further, the detailed kinetic study performed with superior di-site MPTC reveals that the kapp are dependent with the stirring speed, [substrate], [catalyst], [NaOH] and temperature. Based on the kinetic results, thermodynamic parameters are evaluated.
Physical chemistry
Bahman Vasheghani Farahani; Golamreza Rezaei Behbahani; Monir Shalbafan
Volume 5, Issue 3, pp. 237-363, Serial No. 16 , July 2017, , Pages 286-292
Abstract
Thermodynamic study on the interaction of β-CD with poly ethylene oxide and poly acrylic acid was performed by isothermal titration calorimetry at 298K. when β-CD is added to the interpolymer complex, competition is created between host-guest and Hydrogen bond. Enthalpy of interaction between ...
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Thermodynamic study on the interaction of β-CD with poly ethylene oxide and poly acrylic acid was performed by isothermal titration calorimetry at 298K. when β-CD is added to the interpolymer complex, competition is created between host-guest and Hydrogen bond. Enthalpy of interaction between the β-CD and interpolymer complex was calculated using the extended solvation theory. P=1 Shows that willingness of β-CD to interact with both polymers is identical. The positive values of and show that interpolymer complex are stabilized by β-CD . The process is both enthalpy and entropy-driven. The results show that this interaction is exothermic and increases the interpolymer complex stability.
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.
Physical chemistry
Hossein Ghanadzadeh; Ali Ghanadzadeh; Behnam Hosseini nia; Adel Eftekhari
Volume 5, Issue 1, pp. 1-120, Serial No. 14 , January 2017, , Pages 7-15
Abstract
Liquid-Liquid equilibrium data for the (water + Lactic acid + 2-ethy-1-hexanol) ternary system in T=298.2K and P=1atm were determined and tie- lines related to equilibrium data has been drawn in the phases diagram . The reliability of the experimental tie-line data for this system was as confirmed by ...
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Liquid-Liquid equilibrium data for the (water + Lactic acid + 2-ethy-1-hexanol) ternary system in T=298.2K and P=1atm were determined and tie- lines related to equilibrium data has been drawn in the phases diagram . The reliability of the experimental tie-line data for this system was as confirmed by using the Hand and Othmer –Tobias correlations. The tie-line data were correlated by means of the UNIQUAC equation for this ternary system , The average root mean square deviation between the observed and calculated mass fractions was 0.66%. A comparison of the extracting capabilities of this solvent by 1-octanol was made with respect to distribution coefficients and separation factors bases. The results show that extraction of lactic acid from aqueous solutions by 2-Ethyl-1-hexanol is possible and 2-Ethyl-1-hexanol is more appropriate than the other octanol isomer.
Physical chemistry
Mehdi Ghambarian; Zahra Azizi; Mohammad Ghashghaee
Volume 5, Issue 1, pp. 1-120, Serial No. 14 , January 2017, , Pages 28-34
Abstract
Density-functional-based and ab initio calculations were implemented at different computational levels to estimate the binding energy of Zn2+ ion adsorbed on the available sites of a silicate MEL-type adsorbent. B3LYP and MP2 were used in combination with the 6-31G*, 6-31+G*, LanL2DZ, 6-311+G*, and Def2-TZVP ...
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Density-functional-based and ab initio calculations were implemented at different computational levels to estimate the binding energy of Zn2+ ion adsorbed on the available sites of a silicate MEL-type adsorbent. B3LYP and MP2 were used in combination with the 6-31G*, 6-31+G*, LanL2DZ, 6-311+G*, and Def2-TZVP basis sets. The zinc cation was found to preferentially occupy the 6MR sites followed by the cage-like positions. Nevertheles, all of the available sites exhibited negative amounts for the Gibbs free energy and enthalpy of adsorption with the corresponding population-averaged values of –160.84 and –169.53 kcal/mol at the B3LYP/Def2-TZVP level. Overall, the B3LYP/LanL2DZ method illustrated the highest deviation from the others both in trends and absolute values of binding energy. While the absolute binding energy ranged from 131.23 to 230.79 kcal/mol over different sites, the population-averaged binding energies altered from 146.08 to 162.54 kcal/mol depending on the method employed.
Physical chemistry
Bahram Hosseini nia; Azam Anaraki Firooz; Masoumeh Ghalkhani; Javad Beheshtian
Volume 4, Issue 4, pp. 359-490, Serial No. 13 , October 2016, , Pages 483-492
Abstract
In this study, undoped ZnO and doped with Fe and Mn nanostructures were synthesized by hydrothermal method. The morphology of nanostructures was characterized by Scanning Electron Microscope. The electrochemical response of the carbon paste electrode modified with nanoparticles of ZnO and also ZnO doped ...
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In this study, undoped ZnO and doped with Fe and Mn nanostructures were synthesized by hydrothermal method. The morphology of nanostructures was characterized by Scanning Electron Microscope. The electrochemical response of the carbon paste electrode modified with nanoparticles of ZnO and also ZnO doped with Fe and Mn toward levodopa (L-Dopa) was studied. Studies of cyclic voltammetry using provided modified electrode showed electro catalytic properties for electro-oxidation of L-Dopa and a significant reduction in anodic over voltage compared to bare electrode was observed. Best response was obtained in terms of the current enhancement, overvoltage reduction, and reversibility improvement of the L-Dopa oxidation reaction under experimental conditions by modified electrode with zinc oxide nanoparticles doped with iron.
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.
Physical chemistry
Mahdi Rezaei Sameti; Etrat alsadat Dadfar
Volume 4, Issue 1, pp. 1-132, Serial No. 10 , January 2016, , Pages 1-12
Abstract
In this research, we studied the structure, properties and NMR parameters of interaction F2 gas with pristine and 3C-doped (8, 0) zigzag models of boron phosphide nanotubes (BPNTs). in order to reach these aims, we considered four different configurations for adsorption of F2gas on the outer and inner ...
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In this research, we studied the structure, properties and NMR parameters of interaction F2 gas with pristine and 3C-doped (8, 0) zigzag models of boron phosphide nanotubes (BPNTs). in order to reach these aims, we considered four different configurations for adsorption of F2gas on the outer and inner surfaces of BPNTs. The structures of all models were optimized by using density functional theory (DFT).The chemical shielding (CS) tensors at the sites of 11B and 31P nuclei were computed from the optimized structures and then the computed chemical shielding tensors were converted to isotropic chemical shielding (CSI) and anisotropic chemical shielding (CSA). Due to the donor electron effects of 3C doped atoms, the chemical shielding isotropic (CSI) of F2 gas on surface of BPNTs was significantly more than pristine models. The results showed that F2 adsorption on surface of nanotube was exothermic and 3C-doped decreased the adsorption energy values. The calculated results proved that the chemical activity of complex BPNTs/F2 has increased and hence the chemical stability of the nanotube has decreased.
Physical chemistry
Mir Ghasem Hosseini; Elham Shahryari
Volume 4, Issue 1, pp. 1-132, Serial No. 10 , January 2016, , Pages 67-77
Abstract
Composite electrodes of polyaniline/MnO2-Multi walled carbon nanotube (PANI/MnO2-MWCNT), MnO2-MWCNT nanocomposites and MWCNT was produced by the in situ direct coating approach. The supercapacitor performance of the nanocomposites was studied by Fourier transform infrared (FT-IR) spectroscopy and scanning ...
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Composite electrodes of polyaniline/MnO2-Multi walled carbon nanotube (PANI/MnO2-MWCNT), MnO2-MWCNT nanocomposites and MWCNT was produced by the in situ direct coating approach. The supercapacitor performance of the nanocomposites was studied by Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The electrochemical properties of electrodes were also investigated by cyclic voltammetry (CV), galvanostatic charge–discharge and electrochemical impedance spectroscopy (EIS) techniques in 0.5 M Na2SO4. The specific capacitance of 321.47 F. g-1, 277.77 F. g-1 and 80 F. g-1 obtained for PANI/MnO2-MWCNT, MnO2-MWCNT and MWCNT, respectively. The EIS results also showed that the capacitive behavior of MWCNT was improved by the addition of MnO2 and PANI.
Physical chemistry
Vahid Moeini; Seyed Hojatollah Rahimi; Zohre Rakhsha
Volume 4, Issue 1, pp. 1-132, Serial No. 10 , January 2016, , Pages 78-93
Abstract
In this work, we report results of calculations based on the density functional theory of different species metal-ozone, containing mercury, silver and gold. The chosen species range from small molecules and large transition-metal containing ozone with mercury, silver and gold complexes. A comparative ...
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In this work, we report results of calculations based on the density functional theory of different species metal-ozone, containing mercury, silver and gold. The chosen species range from small molecules and large transition-metal containing ozone with mercury, silver and gold complexes. A comparative analysis of the description of the metal-oxygen bond obtained by different methodologies is presented. The topology of the electronic density of the metal-ozone is studied, at DFT level, using the theory of atoms in molecules (AIM) developed by Bader. Thermodynamic variables of reactions have been calculated. The effect of temperature on thermodynamics quantities of the reaction has also been investigated. The LanL2MB basis set for mercury, silver and gold with ozone are used at the B3LYP method. The energy levels of the HOMO and LUMO orbitals compute at the B3LYP/LanL2MB level.
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.
Physical chemistry
Reza Samimi Shalamzari; Simin Mansouri; Akram Eghbali
Volume 3, Issue 4, pp. 283-387, Serial No. 9 , October 2015, , Pages 348-355
Abstract
The conditional formal potential, E°′of Methyldopa has been studied by cyclic voltammetry at the surface of activated glassy carbon electrode (AGCE) as the working electrode in different pH phosphate buffered solutions. The experimental Standard redox potential, E°′, of Methyldopa ...
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The conditional formal potential, E°′of Methyldopa has been studied by cyclic voltammetry at the surface of activated glassy carbon electrode (AGCE) as the working electrode in different pH phosphate buffered solutions. The experimental Standard redox potential, E°′, of Methyldopa is obtained to be 0.72 mV versus SHE (Standard Hydrogen Electrode). E°′ values have also been calculated with the aid of density functional theory (DFT) method at B3LYP/6-311G Basis set in conjunction with a Polarizable Continuum Model (PCM). Innovative application of both Direct and indirect methods resulted in theoretical standard electrode potentials of the studied Methyldopa in the order of 0.68 and 0.74 mV, respectively. These results were found to be in excellent agreement with the experimental value in the order of 0.72 mV.
Physical chemistry
Nasrin Sohrabi; Maryam Dookheh
Volume 3, Issue 3, pp. 180-282,Serial No. 8 , July 2015, , Pages 254-265
Abstract
In this study at first , an azo dye, 2,7- naphthalenediol, 2-[(4-Bromophenyl)azo (BPAND) as a ligand has been synthesized by addition of p-Bromoaniline to the modified montomorillonite K10 clay. This ligand was characterized using 1H-NMR, UV-Vis and IR spectroscopies. Subsequently, its interaction with ...
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In this study at first , an azo dye, 2,7- naphthalenediol, 2-[(4-Bromophenyl)azo (BPAND) as a ligand has been synthesized by addition of p-Bromoaniline to the modified montomorillonite K10 clay. This ligand was characterized using 1H-NMR, UV-Vis and IR spectroscopies. Subsequently, its interaction with calf thymus deoxyribonucleicacid ,ct-DNA was investigated in 5 mM phosphate buffer solution, pH=7 using UV-Vis absorption, thermal denaturation and viscosity measurement. From spectrophotometric titration experiments, the binding constant of BPAND with ct-DNA was found to be (2.89±0.2)×107 M-1 at 25°C. In order to determine changes in thermodynamic properties such as binding constant, Gibbs free energy, binding enthalpy and binding entropy, this experiment was done at various temperatures. The enthalpy and entropy changes were -2.852±0.634 kJ/mol and -814.065 ±2.52 J/mol.K, respectively.Thermal denaturation experiments show the increasing of melting temperature of ct-DNA (about 0.06°C less than 0.6) due to binding of BPAND ligand. From these results the mechanism and the stoichiometry of binding were determined. The results revealed that this interaction is exothermic (negative enthalpy change) along with negative entropy change. Therefore, the driving force in these interactions is enthalpy and the process is enthalpy-driven and suggest that the main driving force for the ct-DNA-BPAND complex formation is being Van der Waals or hydrogen binding.
Analytical chemistry
Narges Ajami; Ali Ehsani; Ferydon Babaei; Ashraf Heidaripour
Volume 3, Issue 2, pp. 72-147, Serial No. 7 , April 2015, , Pages 72-77
Abstract
Optical modeling was applied for obtaining absorbance spectra and band gap values for different morphology of ZnO semiconductor. In optical modeling, the relative permittivity scalars of zinc oxide coral like nanorods were calculated using the Bruggeman homogenization formalism. ZnO nano rods (ZONRs) ...
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Optical modeling was applied for obtaining absorbance spectra and band gap values for different morphology of ZnO semiconductor. In optical modeling, the relative permittivity scalars of zinc oxide coral like nanorods were calculated using the Bruggeman homogenization formalism. ZnO nano rods (ZONRs) as a nucleus layer were fabricated on the Indium Tin Oxide (ITO) by chronoamperometry (CA) in aqueous solution containing different concentration of zinc nitrate. Reduction of nitrate anion is a good resource for hydroxyl ion that with zinc anion results ZnO. The orientation and morphology of both the nucleus layer and successive coral like ZONRs were analyzed using X-ray diffraction (XRD).
Inorganic chemistry
Mahdieh Ghobadifard; Qasem Maleki; Mostafa Khelghati; Ehsan Zamani; Saeid Farhadi; Alireza Aslani
Volume 3, Issue 1, pp. 1-71, Serial No.6 , January 2015, , Pages 26-40
Abstract
ZnO nanostructures of different methods and sizes were grown in a controlled manner using a simple hydrothermal and sonochemical technique. Controlling the content of concentration and temperature of the reaction mixture, spherical nanoparticles ZnO structures could be synthesized at temperatures 100-150 ...
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ZnO nanostructures of different methods and sizes were grown in a controlled manner using a simple hydrothermal and sonochemical technique. Controlling the content of concentration and temperature of the reaction mixture, spherical nanoparticles ZnO structures could be synthesized at temperatures 100-150 °C with excellent reproducibility in solvothermal and at different power and time in sonochemical methods. These ZnO nanostructures have been tested for CO2 gas monitoring by depositing them as thick films on an inter-digitated alumina substrate and evaluating the surface resistance of the deposited layer as a function of operating temperature and CO2 concentrations. The gas sensitivity tests have demonstrated that the ZnO nanostructures, spherical morphology, exhibit high sensitivity to CO2 proving their applicability in gas sensors. The role of the nanostructure on the sensing properties of ZnO is also discussed.
Analytical chemistry
Mohamad Mohsen Momeni; Mohadesah Hakimiyan; Ali Kazempoor; Mahboubeh Mirhosseini; Zohre Nazari; Seyed Mostafa Mirhoseini; Hadi Kargar
Volume 3, Issue 1, pp. 1-71, Serial No.6 , January 2015, , Pages 41-47
Abstract
Cupper Oxide structures with a variety of novel morphologies are synthesized using cupper foil as substrate via a solution route. The structure, morphology and phase of the as-synthesized nanostructures are analyzed by various techniques. SEM images show gradual development of hierarchical structures ...
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Cupper Oxide structures with a variety of novel morphologies are synthesized using cupper foil as substrate via a solution route. The structure, morphology and phase of the as-synthesized nanostructures are analyzed by various techniques. SEM images show gradual development of hierarchical structures of copper oxide with different morphology. In order to study the effect of reaction time and temperature on the morphology of the CuO samples, experiments carried out at temperatures 0 °C and 25 °C for 10 min up to 12h. Results showed that the prepared samples exhibited some novel morphology such as nanorods, nanosheets, microflowers, Cubic shaped structures and Tulip flower-shaped structures.
Physical chemistry
Reza Fazaeli; Mohammad Solimannejad
Volume 2, Issue 4, pp. 236-325, Serial No. 5 , October 2014, , Pages 244-254
Abstract
Density functional (DFT) calculations at M05-2x/aug-cc-pVDZ level were used to analyze the interactions between dimethyl sulfoxide (DMSO) dimers. The structures obtained have been analyzed with the Atoms in Molecules (AIMs) and Natural Bond Orbital (NBO) methodologies. Four minima were located on the ...
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Density functional (DFT) calculations at M05-2x/aug-cc-pVDZ level were used to analyze the interactions between dimethyl sulfoxide (DMSO) dimers. The structures obtained have been analyzed with the Atoms in Molecules (AIMs) and Natural Bond Orbital (NBO) methodologies. Four minima were located on the potential energy surface of the dimers. Three types of interactions are observed, CH•••O, CH•••S hydrogen bonds and orthogonal interaction between the lone pair of the oxygen with the electron-deficient region of the sulfur atom. Stabilization energies of dimers including BSSE and ZPE are in the range 27–40 kJ mol-1. The most stable conformers of dimers at DFT level is cyclic structure with antiparallel orientation of S=O groups that pairing with three C–H…O and a S…O interactions.
Physical chemistry
Morteza Vatanparast; Nabi Javadi; Rasoul Pourtaghavi Talemi; Elahe Parvini
Volume 2, Issue 4, pp. 236-325, Serial No. 5 , October 2014, , Pages 316-325
Abstract
The character of the intermolecular interactions in Cl2-HX (X =F, Cl and Br) complexes has been investigated by means of the second-order Möller–Plesset perturbation theory (MP2) and the density functional theory (DFT) calculations. The results show that there are two types of lowest interaction ...
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The character of the intermolecular interactions in Cl2-HX (X =F, Cl and Br) complexes has been investigated by means of the second-order Möller–Plesset perturbation theory (MP2) and the density functional theory (DFT) calculations. The results show that there are two types of lowest interaction potential equilibrium structures in the interactions between Cl2 and HX: X∙∙∙Cl type geometry and hydrogen-bonded geometry. The calculated interaction energies show that the X∙∙∙Cl type structures are more stable than the corresponding hydrogen-bonded structures. The nature of the intermolecular interactions has been also investigated by natural bond orbital (NBO) and atoms in molecules (AIM). The AIM analysis reveals that both types of intermolecular interactions are “closed-shell” noncovalent interactions.
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