Showing papers in "Computational and Theoretical Chemistry in 2015"

TL;DR: In this paper, the authors used a molecular dynamics simulation method to investigate the absorption behavior, inhibition mechanisms on Fe (1 − 0 − 0) surface in aqueous solution and diffusion behavior of H 3 O +, Cl − and H 2 O in three different base inhibitor films, including 3,5-dibromo salicylaldehyde-2-pyridinecarboxylic acid hydrazide (L1), 3, 5-Dibromosylaldehyde]-2-thiol-phenecarboxyl acid hydride hydraz

TL;DR: The paper collects the answers of the authors to the following questions: what is the significance of topological approach, and can new chemical concepts be found by a topology approach?

TL;DR: In this article, a new molecular hardness equation to calculate chemical hardness of functional groups and molecules is derived utilizing the relationship with charge of the electronic energy for atoms, Density Functional Theory, and Datta's global hardness equalization principle.

TL;DR: In this paper, the performance of three antipyrine derivatives, namely, 4-amino-antipyrine (AAP), SAAP and AAAP, for metal surface corrosion was studied by using quantum chemistry, molecular mechanics and molecular dynamics simulation methods.

TL;DR: In this paper, a methodology to determine the structure and chemical reactivity based on the quantum chemical topology analysis is presented, which is based on QTAIM and ELF frameworks, respectively.

TL;DR: In this paper, the Density Functional Theory (DFT) method and different model chemistries were used to simulate pinocembrin structure and chemical reactivity in order to study the relationship between its structure and antioxidant properties.

TL;DR: In this article, the authors designed heterocyclic azo dyes for dye-sensitized solar cells and performed quantum chemical calculations to determine the open-circuit photovoltage (VOC), and quantify the parameters such as the light harvesting efficiency, the electron injection efficiency associated with the shortcircuit photocurrent density (J SC ).

TL;DR: In this paper, the possibility of investigating non-covalent interactions (NCIs) by using the Reduced Density Gradient (RDG) in tandem with energy densities descriptors is explored.

TL;DR: In this article, a new equation by which group electronegativity can be calculated from ionization energies (I ) and electron affinities (A ) of atoms that constitute the group was obtained.

TL;DR: In this article, the pyran ring break via Retro-Aldol mechanism was kinetically favored over Retro-Diels-Alder mechanism (with C3 C4 bond formed), followed by C6 OH assisted pinacol ring cleavage mechanism, 2′−+2′+−2′ and 2

TL;DR: In this article, the topology of electron density in the interatomic regions using standard protocols of QTAIM, IQA and NCI techniques as well as in-house developed cross-sections of the electron and deformation density distributions was investigated by exploring the nine kinds of inter- and intramolecular interactions.

TL;DR: In this paper, density functional theory (DFT) calculations are performed to study the conformations, hydrogen-bonding network, and the stabilities of all possible molecular associations, urea-H 2 O n, (n ǫ = 1-5) in aqueous solutions of urea.

TL;DR: In this article, intramolecular halogen-halogen interactions in perhalogenated ethanes were investigated using Bader's theory of Atoms in Molecules along the potential energy surface defined by the XCCX′ torsion angle.

TL;DR: In this article, it was shown that high local temperature is associated with nearsightedness of the first-order density matrix, high electron localization, and small values of the bond metallicity.

TL;DR: In this article, the authors used first and second-order density matrices consistent with a closed shell coupled cluster energy to carry out the IQA splitting, and tested and discussed using H2, N2, H2O and CO as representative examples.

TL;DR: In this paper, the intrinsic geometry of the kinetic energy distribution for a series of homonuclear dimers and compare the geometric properties of these distributions with the bond energies of the same dimers.

TL;DR: In this paper, VDW-DF and M06-2X calculations were performed on biphenylene nanostructures to study the hydrogen and lithium storage on them, and the results showed that Li-doped sheet can adsorb 7.4% of H2, with an average AE of −0.20

TL;DR: In this article, the structural, electronic and vibrational properties of 6-Nitro-1,3-benzothiazole-2(3 H )-thione and their 2-thiol tautomer were studied by using density functional theory (DFT) and self consistent reaction force (SCRF) calculations in gas phase and, in formamide, aqueous, DMSO and acetone solutions.

TL;DR: In this article, the thermal decomposition processes of a β-1 linkage lignin dimer model compound 1 (1,2-p-hydroxyphenyl-1,3-propanediol) were theoretically investigated by employing density functional theory methods at B3LYP/6-31G(d, p) level.

TL;DR: In this paper, the B3LYP hybrid density functional method was used to investigate hydrogen adsorption on pure Al n and mixed Al n Si m (n ǫ = 5 − 7, n Â+ǫ m  = 5−7) nano clusters.

TL;DR: In this paper, a new class of nonlinear-optical (NLO) chromophores is proposed, containing quinoxalin-2-one moiety in π-electron bridge.

TL;DR: In this article, the nature of bifurcated halogen bonding in complexes with bidentate heterocycles has been studied through an analysis of the electron density and the electrostatic potential.

TL;DR: In this paper, the authors provide a general vision coming out from MPD on the two main family of bonds: polar-covalent and ionic bonds, showing a prolate shape that extends preferentially in the orthogonal direction to the bond axis, and not along it.

TL;DR: In this article, the first MPD analysis of semi ionic crystals, Silicon Oxide, Aluminum Oxide and Titanium Oxide has been performed on bulk crystal and on surface slab models.

TL;DR: In this article, the solvent dependent excited-state intramolecular proton transfer (ESIPT) dynamics of 1-morpholinylmethyl-2-naphthol (MN) in n -hexane and acetonitrile have been investigated, based on the time-dependent density functional theory, as well as IEFPCM model.

TL;DR: The National Research Foundation of South Africa (Grant No. 87777) and the University of Pretoria (UPS) as discussed by the authors have provided a grant for the work of as discussed by the authors.

TL;DR: In this article, the structure-antiradical properties relationship of flavonoids (chrysin, galangin, pinocembrin and pinostrobin) and phenolic acid (caffeic acid phenethyl ester) commonly found in propolis extracts (PE) was investigated trough M05-2X functional in conjunction with the 6-31G(d,p) and 6- 31+G (d, p) basis sets, considering the structural properties, and free-radical inhibition mechanism: H-atom transfer (HAT

TL;DR: In this article, the authors reexamine the full GVB (or spin-coupled) description of the bonding in the ground state of C 2 at its equilibrium geometry, prompted by recent controversy as to whether or not this system exhibits four bonds.

TL;DR: In this paper, seven functionals, M06-L, PBE0 and B3LYP with two different basis set were used in the determination of the absorption spectrum in two chemical arrangements, Cyanidin (Cy) and CCL (Cy-Cl), trying to reproduce the ethanol/HCl environment of the experimental results.

TL;DR: In this article, a series of 18 Diels-Alder cycloadditions involving four dienes (butadiene, 2-hydroxybutadienes, cyclopentadiene and cyclohexadiene) and variously-substituted ethylenes and acetylenes as dienophiles were investigated.