The electronic structures and the electrostatic potential of some amino derivatives of adamantane have been studied using the density functional theory. The partial atomic charges and nuclear quadrupole coupling constants (NQCC) of 14N nucleus of the considered molecules have been reported. The partial atomic charges are calculated with two methods for 14N nucleus: Mulliken charges and natural ...

In this article, theoretical studies on the selective complexation of the halide ions (F¯, Cl¯ and Br¯) and ion pairs (Na+F¯, Na+Cl¯ and Na+Br¯) with the cyclic nano-hexapeptide (CP) composed of L-proline have been performed in the gas phase. In order to calculate the dispersion interaction energies of the CP and ions, DFT-D3 calculations at the M05-2X-D3/6-31G(d) level was employed. Based on t...

On the basis of electronic structure calculations and molecular orbital analysis, we offer a physical explanation of the observed large decrease (0.9 eV) in ionization energies (IE) in going from hydroxymethyl to hydroxyethyl radical. The effect is attributed to hyperconjugative interactions between the sigma CH orbitals of the methyl group in hydroxyethyl, the singly occupied p orbital of carb...

Ethanol displays two stable conformers, the classic anti (or trans) form and a gauche conformation in which the hydroxyl hydrogen points toward one of the methyl hydrogens. Surprisingly, the two forms have nearly equal energies, and in the vapor phase the gauche form predominates because of its twofold degeneracy. An analysis of the energetics of these conformers based on natural bond orbital a...

Density functional theory dispersion corrected (DFT-D3)calculations and molecular dynamic (MD) simulation were applied to investigate the sensing ability of four types of receptors (RCs) composed of the ortho-phenylenediamine based bis-ureas for selective complexation with the anions such as Cl–, Br–, OAC–, PhCO2–, H2PO4– and HSO4– in the gas phase and DMSO. On the basis of the data obtained fr...

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 hy...

In this study, kinetics and mechanism of the sulfur dioxide adsorption on the single-walled carbon nanotubes (CNT) are investigated. Three single-walled carbon nanotubes, including the armchair (6,6), chiral (6,5) and zigzag (6,0) CNTs were chosen as the models and the different orientations of SO2 molecule relative to the CNT axis were considered. The B3LYP functional within the 6-3...