Cristalografia estrutural: minerais e compostos bioativos

Abstract

The X-ray difraction is a powerful tool in the analysis of materials. This technique allows studies to identification of the constituents in a sample crystalline, structural analysis and analysis of electronic charge density distribution in chemical bonds. In this work, structural studies by X-ray difraction were realized in compounds of natural origin (sodalite and garnets), in the nevirapine (antiretroviral drug) and its solvates and in a salt of cobalt(II) of quinolinic acid. The first trials were conducted to estimate the effects of different forms of treatments in diffraction data collected in type CCD detectors and high redundancy. Analyses allowed for the description of the chemical and structural formulae of minerals, through the refinement of the occupations of the crystallographic sites: sodalite - Na8,0(1)Al5,99(7)Si6,03(7)Cl1,98(2)O24,1(4) -; garnet from diamantina - {Ca2,96Fe0,04}[Al1,28(1)Fe0,70(1)Ti0,03](Si3)O12 -; garnet from teófilo otoni - {Fe2,02(4)Mg0,617(9)Mn0,29(4)Ca0,08}[Al2](Si3)O12. About the drug nevirapine, it was possible to the resolution and characterization of new solvates crystalline: nevirapine hemihydrate and nevirapine hemiethyl acetate. This last is an unstable compound and it may be converted in other forms crystalline of nevirapine. For the derivative of quinolínico acid, in addition to the structural analysis, the distribution of electron density was realized through of the Fourier maps.