Tesis doctoral de María Lourdes Roset Calzada
Molecular engineering is based on the knowledge of the stereoelectronic features that define the molecular recognition, which is the result of the complementarity of geometric and electronic features between two different molecular entities. The importance of different electrostatic contributions allows us to make a theoretical prediction of molecular properties, from calculations of electrostatic potential and molecular polarization. This work is based on the study of the use of maps of electrostatic potential and polarization potential as molecular descriptors. first there is a study of the effect of the basis set and the methodology used in the calculation of first and second order electrical properties. The analysis was carried out with the molecules of hydrogen cyanide, formaldehyde and urea. The base sets used are the standard double-zeta, to which were added polarization and diffuse functions. In particular, we have used the double zeta basis 6-31g (d), double zeta basis augmented with one or two sets of polarization functions: 6-31g (d, p), 6-31g (2d, 2p) and also used the base 6-311g + + (2d, 2p), which includes diffuse functions. The different levels of calculation methodologies used hartree-fock, moller-plesset second and fourth order and the theory of density functional (dft): scf, mp2, mp4, blyp b3lyp i. We analyze the effect of different sets based on the contribution of polarization to the interaction energy, calculated for each system of first order properties, such as dipolar moments and quadrupolar moments, and second order properties such as polarizability and molecular hyperpolarizability. further, the effect of the basis and method on the calculation of the electrostatic potential and molecular polarization potentials is evaluated. For this purpose we performed a comparative study of the maps calculated with different basis sets and methodologies, in particular a study of the spatial distribution and correlation analysis between the different data bases and methodologies was done. An analysis of molecular polarization maps by calculating the differences in polarization and relative standard deviation allows for a comparative study of different methodologies and bases used. Specifically, a comparative analysis between different methods of calculating the base 6-311g + + (2d, 2p), calculated by reference to the mp4 was done. we use maps of electrostatic, polarization and interaction potentials for the analysis of molecular recognition features of a set of bioactive compounds, to discuss the importance of the contribution of polarization. For this reason, we choose to study a set of molecules with high polarizability, specifically, two families of compounds with heavy atoms of chlorine and defined toxic activity, which are part of groups of dioxins and furans. A study of the polarization maps as indicators of biological activity of dioxins and furans, based on the best methodology is done. The inclusion of polarization as a molecular descriptor for predicting biological activity of dioxins and furans was studied from the calculation of electrostatic potentials and polarization, an analysis of the potential maps, and defining the main areas of interaction molecular electrostatic and polarization interaction from calculations of principal components (pca) and the prediction of biological activity based on a study by calculation of partial least squares (pls).
Datos académicos de la tesis doctoral «Estudi de la utilització dels mapes de potencial electrostÁ tic i de polarització com a descriptors moleculars«
- Título de la tesis: Estudi de la utilització dels mapes de potencial electrostÁ tic i de polarització com a descriptors moleculars
- Autor: María Lourdes Roset Calzada
- Universidad: Politécnica de catalunya
- Fecha de lectura de la tesis: 18/11/2011
Dirección y tribunal
- Director de la tesis
- Juan Jesús Perez Gonzalez
- Tribunal
- Presidente del tribunal: Ana María Sastre requena
- hugo Omar villar (vocal)
- Jaime Rubio Martinez (vocal)
- ibón Alkorta osoro (vocal)