Espectroscopia vibracional em cristais de D-valina sob condições ambientes

Abstract

This work have with principal objective to investigate the normal modes of vibration of the amino acid crystal D- valine . For this purpose, initially the reagent which was in powder form was crystallized by the method of slow evaporation of the solvent , which allowed to obtain crystals in the form of plates. In the second stage there was the investigation of the crystal from the perspective of Raman spectroscopy using a spectrometer of WITec with type detection charge-coupled device (CCD) cooled liquid nitrogen. We conducted the measurement of Raman spectroscopy at ambient conditions of temperature and pressure. The measured spectral region extended from 85 cm-1 to 3100 cm-1, and there are 61 modes of vibration. Most of the observed vibrational modes is also present in the spectrum of L-valine, although a few have not been observed in the L form, as was the case of the vibrational mode found at 716 cm-1. A classification attempt to all the observed vibrational modes was made, with the classification by reference to work done both in L-valine as for other aliphatic amino acids.