Applicability studies for a novel alternative method for calculation of core electron binding energies (CEBEs) as new molecular descriptors in medicinal chemistry and related areas

• Processo: 03/09007-6
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Data de Início da vigência: 01 de fevereiro de 2004
• Data de Término da vigência: 31 de janeiro de 2005
• Área de conhecimento: Ciências Exatas e da Terra - Química - Físico-química
• Pesquisador responsável: Yuji Takahata
• Beneficiário: Rudolf Kiralj
• Instituição Sede: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brasil
• Vinculado ao auxílio: 03/00075-9 - Desenvolvimento de um método alternativo para o cálculo de energia de ionização de camadas internas (CEBE) de moléculas, e avaliação da utilidade de CEBE na modelagem molecular de fármacos, AP.TEM
• Assunto(s): Relação quantitativa estrutura-atividade Teoria do funcional da densidade
• Palavra(s)-Chave do Pesquisador: Core Electron Binding Energies | Density Functional Theory | Esca Chemica Shifts | Molecular Descriptors | Qsar/Qspr

Resumo

X-ray Photoelectron Spectroscopy (XPS) or Electron Spectroscopy for Chemical Analysis (ESCA) is a relatively new X-ray based spectroscopy. Experimental core-electron binding energies (CEBEs) for electrons defined by atomic number, principal and azimuthal quantum number, when measured by this technique, Show systematic variations depending on atom environment, presumably due to changes in the atom oxidation state and valence shell. Computational methodologies based on Density Functional Theory (DFT) and semi-empirical (HAM/3) approaches are able to reproduce well the CEBE shifts (CEBEs relative to standards) known as ESCA chemical shifts. The aim of this project is to investigate the usefulness of new methodology to calculate ESCA shifts (at DFT and HAM/3 level) in medicinal chemistry, QSAR/QSSPR studies and related areas. It is presumed that, due to valence electron density changes, calculated ESCA shifts can be related to molecular descriptors, (hetero)aromaticity indices, biological activity/toxicity, physico-chemical and spectroscopic properties, chemical reactivity and intermolecular interactions at quantitative level. To test this statement, carbon 1s and other shifts in benzene derivatives, polycyclic aromatic hydrocarbons, artemisinins, indole-3-acetic acid and HIV-1 protease inhibitors will be related to the aforementioned phenomena and parameters. (AU)