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Theoretical studies of interactions in cyprodinil-α-cyclodextrin and cyprodinil-β-cyclodextrin systems

Hołaj-Krzak Jakub T.

Journal of Water and Land Development

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2023

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no. 57

9--20

EN

The paper presents the results of theoretical calculations in terms of the G4MP2 composite method for cyprodinil-α-cyclodextrin (C0@α-CD) and cyprodinil-β-cyclodextrin (C0@β-CD) systems. Studies also covered analogous systems consisting of the anion (C-) and the cation (C+) of cyprodinil. The geometries of the cyprodinil molecule and ions were optimized on the basis of the DFT theory, using hybrid (B3LYP, PBE0), pure (B97-D) and “meta” (M06-2X) GGA functionals for selected Pople basis sets [6-311++G(d,p), 6-311++G(2d,p), 6-311++G(2d,2p)] and Dunning basis set (aug-cc-pVDZ). The research results suggest that the affinity of “guest” molecules for “hosts” is relatively low. Theoretical studies of the “guest-host” systems allow to predict the properties of the designed preparations.

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Effect of the Dielectric Medium on the Conformational Behaviour of Methyl 3-Nitrobenzoate

Konopacka A., Kalenik J., Pawełka Z.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 9

1583-1592

EN

Conformational analyses of methyl 3-nitrobenzoate (MNB) was performed, employing DFT, MP2, and semi-empirical quantum-chemical calculations, as well as classical methods based on atomic charge and dipole moment approximations. Properties such as the relative energies of the O-NO2 trans and O-NO2 cis isomers, their populations and dipole moments, all in vacuum, were considered first. Then the conformational trans cis equilibrium was quantitatively established by dipole moment measurements in solvents of dielectric permittivities between 2.016 and 10.34. Different approaches, based on continuum-dielectric and MSAmodels were explored to explain the contribution of the electrostatic interaction to the standard Gibbs energy change delta G° of the trans cis transformation in MNB in solution.

3

A Theoretical Study on (eta5-C5H5)Fe(CO)(PPh3)(C(O)CHMe) Anion Structure and Stereoselectivity

Anisimov V., Bartnicka E., Dybała-Defratyka A., Paneth P.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 5

737-744

EN

Organometallic systems provide an exceptional tool in the stereoselective synthesis. The source of this selectivity, however, frequently remains a challenging question. In recent years, theoretical studies of mechanisms of organometallic and metalloprotein catalysis have received considerable attention. The density functional theory (DFT) methods have been shown to be very successful in these studies. Their application, however, is still limited by the performance of the present computers. As the result, a new class of methods, which employ quantum mechanical calculations combined with either semiempirical and/or molecular mechanics levels (QM/MM), has been developed. This stimulated development of a number of new semiempirical methods, which can handle metals. We present a comparison of a few of these new methods with the DFT level on the example of the acetyliron. In addition, the DFT calculations are used to shed some light on the mechanism of the stereospecific catalysis by acetyliron.