Physical chemistry
Pouya Karimi; Mahmoud Sanchooli
Volume 2, Issue 3, pp. 162-231, Serial No. 4 , July 2014, , Pages 173-179
Abstract
Stability of the π-π stacking interactions in the Ben||N-substituted-coronene complexes was studied using the computational quantum chemistry methods (where Ben is benzene and || denotes π-π stacking interaction, and N-substituted-coronene is coronene molecule which substituted with different ...
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Stability of the π-π stacking interactions in the Ben||N-substituted-coronene complexes was studied using the computational quantum chemistry methods (where Ben is benzene and || denotes π-π stacking interaction, and N-substituted-coronene is coronene molecule which substituted with different number of N atoms). The results reveal simultaneous effects of structure and number of Heteroatom on the π-π stacking interactions with N-substituted-coronenes. Changing the number of Heteroatom N in N-substituted-coronenes and substitution of 8N-coronene with electron-withdrawing or electron-donating X groups alter the electron charge density at rings of this molecule and leads to different binding energies in the Ben||X-8N-substituted-coronene complexes. Results indicate that electron-withdrawing groups lead to higher π–π stacking binding energies compared to electron-donating ones in the Ben||X-8N-substituted-coronene complexes.
Nanochemistry
Mahdi Rezaei Sameti; Nina Alisafarzadeh
Volume 2, Issue 3, pp. 162-231, Serial No. 4 , July 2014, , Pages 209-221
Abstract
The aim of this research is studying the effects of Ge-doped on CO adsorption on the outer and inner surfaces of (6, 0) zigzag model of boron nitride nanotube (BNNTs) by using DFT theory. For this purpose, eight models of CO adsorption on the surfaces of BNNTs are considered. At first step, all structures ...
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The aim of this research is studying the effects of Ge-doped on CO adsorption on the outer and inner surfaces of (6, 0) zigzag model of boron nitride nanotube (BNNTs) by using DFT theory. For this purpose, eight models of CO adsorption on the surfaces of BNNTs are considered. At first step, all structures were optimized at B3LYP and 6-31G (d) standard base set and then the electronic structure, adsorption energy, HOMO - LUMO orbitals, gap energy, quantum molecular descriptors, and NQR parameters were determined. The bond lengths neighborhood sites of Ge-doped of BNNTs at all models were increased and the bond angles decreased. The small adsorption energy value and large interaction distance show that the adsorption of CO on BNNTs is weakly physical adsorption due to weak Van der Waals interaction. Our calculated results show that the adsorption of CO on the surface of undoped models is more favorable than Ge-doped models. The NQR parameters of the first layer in all the models are larger than those other layers.
Analytical chemistry
Behnam Hafezi
Volume 2, Issue 3, pp. 162-231, Serial No. 4 , July 2014, , Pages 222-231
Abstract
In this work, a tracer study on pore initiation in anodic alumina in oxalic acid was performed. Effects of some experimental parameters such as applied electrical potential, electrolyte composition and heat pretreatment were evaluated. Electrochemical and morphological experiments were performed using ...
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In this work, a tracer study on pore initiation in anodic alumina in oxalic acid was performed. Effects of some experimental parameters such as applied electrical potential, electrolyte composition and heat pretreatment were evaluated. Electrochemical and morphological experiments were performed using potentiostatic anodizing and scanning electron microscopy (SEM) techniques, respectively. Effect of electrolyte composition on current density was discussed. In various electrical potentials, electrolyte composition had different effects on current density. Addition of sulfuric acid into oxalic acid increased porosity. Also, distribution of pore size and pore diameter were influenced by presence of sulfuric acid. Effect of electrolyte composition on the morphology of aluminum surface layer was depended on to the electric potential. Current density and porosity of aluminum surface layer was decreased by heat pretreatment.
Physical chemistry
Reza Behjatmanesh; Negin Safaeian
Volume 2, Issue 2, pp. 82-163, Serial No. 3 , April 2014, , Pages 147-156
Abstract
: In this work, different levels of theory containing HF, B3LYP, and MP2 with different basis sets such as 6-31G, 6-31G*, 6-311G, 6-311+G, 6-31+G*, 6-31+G are used to predict relative acidity constants of some aniline derivatives. Three different kinds of radii containing UAHF, Bondi, and Pauling are ...
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: In this work, different levels of theory containing HF, B3LYP, and MP2 with different basis sets such as 6-31G, 6-31G*, 6-311G, 6-311+G, 6-31+G*, 6-31+G are used to predict relative acidity constants of some aniline derivatives. Three different kinds of radii containing UAHF, Bondi, and Pauling are used to study how cavity forms change acidity constants. In all cases, DPCM model is used to simulate solvation Gibbs free energy. Furthermore, one similar level and basis set has been linked to IEFPCM and DPCM models to compare the results. To relate gas-phase Gibbs free energy to the solution Gibbs free energy, a simple thermodynamic cycle is used. Results show that quantum chemical calculations are robust techniques for estimating acidity constants.