In this study, electronic structures of ground state of pure vanadium sub-nano clusters, Vn (n=2-5), and their interactions with small ligands for example CO and triplet O2 molecules are investigated by using density functional theory (DFT) calibration at the mPWPW91/QZVP level of theory. The favorable orientations of these ligands in interaction with pure vanadium sub-nano clusters were determ...

in the present study, the interactions of three different lithium species li+, li3+ and ch3li with several different sites of the most stable tautomers of dna nucleo-bases are presented. this investigation is based on the results of thermochemical properties, quantum theory of atoms in molecules (qtaim) and natural bond orbital (nbo) analysis, obtained at b3lyp/6-311++g(d,p) level of theory. th...

A theoretical study was performed to evaluate the defersirox potency to chelate aluminum (Al) and gallium (Ga) as the toxic metals in biological systems. Deferasirox as an important class of chelators, which binds to the metallic center with the ratio of 1:2, is used to remove the toxic metals in the case of iron overload disease. The effects of water and DMSO as the solvent on the electronic n...

This research has been carried out to study and find a rather general description for a lone pairorbital in molecules. Since the orbital parameters must be manageable in advance, and correctgeometry of the molecule (bond lengths) is depend on the appropriate lone pair description; theFSGO method including optimization has been used to obtain orbital parameters and energy. Theproposed models for...

dft-gga method of perdew-burke-ernzerhof (pbe) is used with aug-cc-pvtz, 6-311++g**, and def2-tzvp large basis sets to study the hydrogen bond interactions between oxygen lone pair as a donor electron with hydrogen atom connected to the aniline’s nitrogen as an electron acceptor (h2o···hnh-ph), and nitrogen lone pair with hydrogen of water molecule (ph-h2n···hoh), both in the gas phase. in some...

the influence of cation-π interactions on the strength and nature of intramolecular o...h hydrogen bond has been investigated by quantum chemical calculations in orthohydroxy benzaldehyde (hba) compound. ab initio calculations have been performed at mp2/6-311++g** level of theory. vibrational frequencies and physical properties such as chemical potential and chemical hardness of these compounds...

Interaction of proline with gold cluster was studied using density functional theory (DFT). Two types of mixed basis sets UB3LYP/6-311++G ∪ LANL2MB and UB3LYP/6-311++G ∪ LANL2DZ were used for optimization of complex structures. Proline interacts with gold cluster either through one anchor bond, N–Au or an anchor bond O–Au associated with a non-conventional O–H. . . Au hydrogen bond. Among these...

In this research work at The first compounds [C60- 2-(naftalin-1-ilmetil)-4,5-dihidro-1H-imidazol-C65-2X]+ (X=F,Cl,Br) were optimized. Then the calculation of natural bond orbitals was performed with the NBO technique. All calculations using Hartree- fock  the 6-31G * basis set using Gaussian 98 software and in gas phase has been done. The results showed that the energy levels of mol...

The complexes formed by H2CO, CH3CHO, and (CH3)2CO with 1, 2, and 3 molecules of CO2 are studied by ab initio calculations. Three different types of heterodimers are observed, most containing a tetrel bond to the C atom of CO2, and some supplemented by a CH⋅⋅O H-bond. One type of heterodimer is stabilized by an anti-parallel arrangement of the C=O bonds of the two molecules. The binding energie...