Implementação da nova técnica espectroscopia Raman por elipsometria no estudo de moléculas quirais

Abstract

The Raman Optical Activity (ROA) has been offered numerous information about the conformation of chiral molecules, an these, has great relevance in many areas, including Biology and Medicine. In present work we investigated a new technique to measure the Raman Optical Activity of chiral molecules: the Raman Spectroscopy by Ellipsoetry (RaSE). The technique ROA quantifies the vibrational optical activity through measurement of a small difference in the intensity of Raman scattering for chiral molecules in incidence of polarized circularly right and left laser light. The RaSE is the application of ellipsometry to measure the Raman scattering, that means, through the technique of ellipsometry we can measure the Stoke parameters, which describe the polarization state of light. The exciting source in RaSE is a laser light beam which can be decomposed into two polarizations: a beam of circularly polarized light right or left. Therefore, the parameter S3 describes the amount of light and when normalized ROA is the acquired signal, therefore provide the difference of intensity of Raman scattering. With this concepts, we performed measurements of RaSE using alcohol (S)-(−)-1-phenylethanol (1-PhEtOH), that was the first chiral substance been characterized using the Raman Optical Activity. The spectrum ROA of 1-PhEtOH using the RaSE is fully agreement with the literature and proves the veracity of the results of RaSE.