Publications by authors named "Hooriye Yahyaei"

In the present work, the quantum theoretical calculations of the molecular structures of the three newly synthesized azomethine dyes: have been predicted using Density Functional Theory (DFT) in solvent dimethylformamide (DMF). The geometries of the azomethine dyes were optimized using the PBE1PBE/6-31+G level of the theory. In addition, the electronic spectra of these compounds in solvent DMF were carried out using the TDPBE1PBE, TDPBEPBE, TDB3LYP methods with 6-31G, 6-31+G, 6-31+G*, 6-31++G* basis sets.

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Contrary to the published conclusions in the literature concerning the origin of the generalized anomeric relationships in open-chain nonplanar systems, its origin has remained an open question. In order to explore the origin of the generalized anomeric relationships in open-chain nonplanar systems, we assessed the roles and contributions of the effective factors on the conformational properties of methyl propargyl ether (1), methyl propargyl sulfide (2), and methyl propargyl selenide (3) by means of the G3MP2, CCSD(T), MP2, LC-ωPBE, and B3LYP methods and natural bond orbital (NBO) interpretations. We examined the contributions of the hyperconjugative interactions on the conformational preferences of compounds 1-3 by the deletions of the orbitals overlapping from the Fock matrices of the gauche- and anti-conformations.

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Natural bond orbital (NBO), nuclear magnetic resonance (NMR) analysis and hybrid-density functional theory based method (B3LYP/Def2-TZVPP) were used to investigate the correlation between the nucleus-independent chemical shifts [NICS, as an aromaticity criterion], σ Al(1)-X2(b) → σ*Al(3)-X₄(b) electron delocalizations and the dissociation energies of Al₂F₆, Al₂Cl₆, Al₂Br₆ and Al₂I₆ to 2AlX₃ (X = F, Cl, Br, I). The results obtained showed that the dissociation energies of Al₂F₆, Al₂Cl₆, Al₂Br₆ and Al₂I₆ decrease from Al₂F₆ to Al₂I₆. Like aromatic molecules, these compounds have relatively significant negative NICSiso(0) values.

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Ab initio molecular orbital (MP2/6-311+G**//MP2/6-31G+G**) and hybrid-density functional theory (B3LYP/6-311+G**//MP2/6-311+G**) methods and NBO analysis were used to study the stereoelectronic interaction effects on the conformational properties of hydrogen peroxide (1), hydrogen disulfide (2) and hydrogen diselenide (3). The results showed that the Gibbs free energy difference (G(T)-G(S)) values at 298.15K and 1atm between the skew (S) and trans (T) conformations (DeltaG(T-S)) increase from compound 1 to compound 2 but decrease from compound 2 to compound 3.

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