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دسترسی آزاد مقاله
1 - The structural properties of boron and nitrogen adsorption on benzene molecule: a density functional study
Samaneh S. Hoseini Edris FaizabadiAbstractThe structural properties of boron and nitrogen atoms added on benzene (Bz) molecule are studied using density functional theory within Gaussian 03 program package. The adsorption energy, HOMO–LUMO energy gap (ΔH–L) and also the optimized bond lengths (C–C and C چکیده کاملAbstractThe structural properties of boron and nitrogen atoms added on benzene (Bz) molecule are studied using density functional theory within Gaussian 03 program package. The adsorption energy, HOMO–LUMO energy gap (ΔH–L) and also the optimized bond lengths (C–C and C–H bond lengths) of the structures are evaluated. In this work, three adsorption sites for both boron and nitrogen were selected, hollow site (H), middle site (M) and top site (T), as their initial positions. It is found that for boron adsorption on Bz molecule, the relaxed middle site configuration has the most stable geometry, while in NBz, we obtained similar positions after optimization process. We have also illustrated that the relaxed NBz positions are in higher stability than the relaxed BBz positions. As a consequence, it is found that the stability of an isolated benzene molecule increases by adding boron or nitrogen on top of it. پرونده مقاله -
دسترسی آزاد مقاله
2 - Formulation of atomic positions and carbon–carbon bond length in armchair graphene nanoribbons: an ab initio study
Mehran Balarastaghi Vahid AhmadiAbstractIn this paper, we investigate the atomic positions of single layer armchair graphene nanoribbon for two cases, with and without hydrogen-passivate edges, accurately and propose a formula which either removes the need of structural relaxation generally or decreas چکیده کاملAbstractIn this paper, we investigate the atomic positions of single layer armchair graphene nanoribbon for two cases, with and without hydrogen-passivate edges, accurately and propose a formula which either removes the need of structural relaxation generally or decreases its time extremely (up to seven times). We also propose a general pattern (hyperbolic) for these positions. On the other hand, we show that edge effect influences several atoms near the edge not just one. These results can be used in software, which compute atomic positions and can increase their efficiency. In addition, we prove that the C–C bond distance depends on dimer number and differs in length and width directions, especially for narrow AGNRs. The maximum value of these differences is about 0.017 Å. پرونده مقاله -
دسترسی آزاد مقاله
3 - conformational properties and the anomeric effect study of phosphinanes
Javad Azizian Mahdieh Entezari Hossein Anaraki Ardakani Shahab ZomorodbakhshAb initio HF/6-31G* Methode was employed to calculate the bond length in 2- phosphinanes when electronegative groups was at C-2 tend axial and equatorial positions. The magnitude of the anomeric effect depends on the nature of the substituent, the effect of the substitu چکیده کاملAb initio HF/6-31G* Methode was employed to calculate the bond length in 2- phosphinanes when electronegative groups was at C-2 tend axial and equatorial positions. The magnitude of the anomeric effect depends on the nature of the substituent, the effect of the substituent can be seen by comparing the bond length in 2-chloro and 2- boromo substituented phosphinanes. The effect of anomeric effect have been effected on the bond length in 2-phosphinanes. پرونده مقاله -
دسترسی آزاد مقاله
4 - Theoretical study of conformational properties and the anomeric effect study of the 2- phosphinanes
Javad Azizian Hossein Anaraki Ardakani Shahab ZomorodbakhshAb initio HF/6-31G* Methode was employed to calculate the bond length in 2- phosphinanes when electronegative groups was at C-2 tend axial and equatorial positions. The magnitude of the anomeric effect depends on the nature of the substituent, the effect of the substitu چکیده کاملAb initio HF/6-31G* Methode was employed to calculate the bond length in 2- phosphinanes when electronegative groups was at C-2 tend axial and equatorial positions. The magnitude of the anomeric effect depends on the nature of the substituent, the effect of the substituent can be seen by comparing the bond length in 2-chloro and 2-boromo substituented phosphinanes. The effect of anomeric effect have been effected on the bond length in 2- phosphinanes. پرونده مقاله -
دسترسی آزاد مقاله
5 - Theoretical study of conformational properties and the anomeric effect study of the 2- phosphinanes
Javad Azizian Mahdieh Entezari Hossein Anaraki Ardakanib Shahab ZomorrodbakhshAb initio HF/6-31G* Methode was employed to calculate the bond length in 2- phosphinanes when electronegative groups was at C-2 tend axial and equatorial positions. The magnitude of the anomeric effect depends on the nature of the substituent, the effect of the substitu چکیده کاملAb initio HF/6-31G* Methode was employed to calculate the bond length in 2- phosphinanes when electronegative groups was at C-2 tend axial and equatorial positions. The magnitude of the anomeric effect depends on the nature of the substituent, the effect of the substituent can be seen by comparing the bond length in 2-chloro and 2-boromo substituented phosphinanes. The effect of anomeric effect have been effected on the bond length in 2- phosphinanes. پرونده مقاله