Quantum Chemistry Group

Arāk, Iran

Quantum Chemistry Group

Arāk, Iran
SEARCH FILTERS
Time filter
Source Type

Solimannejad M.,Quantum Chemistry Group | Gharabaghi M.,Quantum Chemistry Group | Alkorta I.,Institute Quimica Medica | Sanchez-Sanz G.,Institute Quimica Medica
Structural Chemistry | Year: 2012

Ab initio calculations at MP2 computational level using aug-cc-pVTZ basis set were used to analyze the interactions between 1:1 and 1:2 complexes of acetylene and nitrosyl hydride. The structures obtained have been analyzed with the atoms in molecules and the density functional theory-symmetry adapted perturbation theory methodologies. Four minima were located on the potential energy surface of the 1:1 complex. Twenty-four different structures have been obtained for the 1:2 complexes. Five types of interactions are observed, CH·O, CH·N, NH·π hydrogen bonds and orthogonal interactions between the π clouds of triple bond, or the lone pair of oxygen with the electron-deficient region of the nitrogen atom. Stabilization energies of the 1:1 and 1:2 clusters including basis set superposition error and ZPE are in the range 3-8 and 6-17 kJ mol-1 at MP2/aug-cc-pVTZ computational level, respectively. Blue shift of NH bond upon complex formation in the ranges between 18-30 and 20-96 cm-1 is predicted for 1:1 and 1:2 clusters, respectively. The total nonadditive energy in the 1:2 cluster, calculated as the sum of the supermolecular nonadditive MP2 energy and the three-body dispersion energy, presents values between - 1.48 and 1.20 kJ mol-1. © Springer Science+Business Media, LLC 2011.


Solimannejad M.,Quantum Chemistry Group | Rezaei Z.,Quantum Chemistry Group | Esrafili M.D.,Islamic Azad University at Maragheh
Molecular Physics | Year: 2014

UMP2 calculations with aug-cc-pVDZ basis set were used to analyse intermolecular interactions in R3C···XCN· ··LiCN and R 3C···LiCN···XCN triads (R = H, CH3; X = Cl, Br) which are connected via lithium bond and halogen bond. To understand the properties of the systems better, the corresponding dyads are also studied. Molecular geometries and binding energies of dyads, and triads are investigated at the UMP2/aug-cc-pVDZ computational level. Particular attention is paid to parameters such as cooperative energies, and many-body interaction energies. All studied complexes, with the simultaneous presence of a lithium bond and a halogen bond, show cooperativity with energy values ranging between -1.20 and -7.71 kJ mol-1. A linear correlation was found between the interaction energies and magnitude of the product of most positive and negative electrostatic potentials (VS,maxVS,min). The electronic properties of the complexes are analysed using parameters derived from the atoms in molecules (AIM) methodology. According to energy decomposition analysis, it is revealed that the electrostatic interactions are the major source of the attraction in the title complexes. © 2013 © 2013 Taylor & Francis.


Solimannejad M.,Quantum Chemistry Group | Korkani Z.,Quantum Chemistry Group | Esrafili M.D.,Islamic Azad University at Maragheh
Zeitschrift fur Physikalische Chemie | Year: 2014

Density functional theory calculations were used to analyze the interactions in 1: 1 and 1: 2 complexes of naphthalene (NAP) with dimethyl ether (DME). The structures of complexes have been determined using M05-2X density functional and the aug-cc-pVDZ basis set. The structures obtained were analyzed with the quantum theory of atoms in molecules (QTAIM), the energy decomposition analysis, and many-body interaction energies methodologies. Two minima were located on the potential energy surface of the 1: 1 complexes. Four different structures have been obtained for the 1: 2 complexes. Two types of interactions are observed, CH···O and CH···π hydrogen bonds. Interaction energies of the 1: 1 and 1: 2 complexes are in the range 9-12 kJ mol-1 and 20-27 kJ mol-1, respectively, at the M05-2x/aug-cc-pVDZ level of theory.

Loading Quantum Chemistry Group collaborators
Loading Quantum Chemistry Group collaborators