Quantum chemical study

In this paper, the calculation was done to determine the magnetic exchange of the studied molecules, Schiff base complexes via DFT calculations. Using the ZORA approach with the BP86 functionals and appropriate basis set def2-tzvp and Coulomb fitting, the optimized geometries were obtained with reliable accuracy and precision. The dipole moment was calculated.

5p vikwong 29-09-2024 4 1   Download

This global minimum structure has the shape of a tetragonal bipyramid having two Sc atoms at two tops of pyramids binding with one edge of Ge-Ge. The ground electronic state of the global minimum isomer is the 2B2 state in the C2v symmetry. The most stable isomer of Sc2Ge6 − has been used to study the CO adsorption. The calculated results indicate that the Sc2Ge6 − cluster has a good interaction with the CO molecule. The adsorption positions are around the Sc atom with two stable models include adsorbing the C atom and adsorbing both the C and O atoms of the CO molecule.

7p dianmotminh02 03-05-2024 4 2   Download

DFT calculations indicate that the decomposition reaction of nitroethyl benzoates in the presence of 1,3-dimethylimidazolium cation takes place much faster than in the case of the non-catalyzed process. Additionally, our calculations suggest one-step polar mechanism of title reactions.

8p tocectocec 25-05-2020 13 1   Download

The quantum-chemical modeling mechanism of the [4+2]-cycloaddition reaction of 2,3 dimethylbuta-1,3-diene and methyl acrylate was conducted. Its qualitative aspects were analyzed at the molecular level by the program MOPAC2012 and semiempirical method RM1.

6p tocectocec 25-05-2020 7 1   Download

Two heterocyclic oximes (E)-N-hydroxy-1-(pyridin-2-yl)methanimine (Hp2ylm) and (E)-N-hydroxy-1-(pyridin-3-yl)methanimine (Hp3ylm) were synthesized from pyridine-2-carbaldehyde and pyridine-3-carbaldehyde, respectively.

12p tocectocec 25-05-2020 9 2   Download

The basic properties of zeolites were studied by using quantum-chemical calculations. The obtained results have demonstrated that the basicity of zeolites in the forms of alkali cations (Li, Na or K) is increased with increasing cation radius. While the Si/Al ratio in the framework increases, the basicity of zeolites decreases. The application of adsorption method using acidic gases (CO2) for determining basicity may be suitable for solid bases without exhanged ion, but not for zeolites.

6p uocvong04 24-09-2015 66 3   Download

Chemical doping nitrogen in to TiO2 crystal network by methods of sol-gel and impregnation was presented. The obtained nitrogen-doped TiO2 materials were characterized by different techniques such as XRD, SEM, UV-VIS. It was shown that samples have very uniform nano size, anatas structure and low level of band-gap energy (Ebg ~ 2.2 eV, ~ 500 - 600 nm). Their activity and kinetic were also studied and the results proved that in comparison with P25, the obtained nitrogen-doped TiO2 had higher activity and photo-quantum efficiency in organic disintegrated reaction under solar radiation.

6p uocvong01 24-09-2015 52 8   Download

A catalytic turnover of supercoiled DNA (scDNA) transformation medi-ated by topoisomerases leads to changes in the linking number (Lk) of the polymeric substrate by 1 or 2 per cycle. As a substrate of the topoisomeri-zation reaction it is chemically identical to its product; even a single catalytic event results in the quantum leap in the scDNA topology.

8p dell39 27-03-2013 33 4   Download