TLC-SERS of mauve, the first synthetic dye

Abstract

Copyright © 2014 John Wiley & Sons, Ltd. Mauve was the first synthetic organic dyestuff to be manufactured industrially. It was synthesized in 1856 by William H. Perkin. It is composed by different molecules named mauveine A, B, B2 and C. In this study, the dye was synthesized, and its individual components were analyzed by ordinary Raman spectroscopy (both dispersive and Fourier-transform-), and surface-enhanced Raman spectroscopy, after separation by thin-layer chromatography. Only surface-enhanced Raman scattering (SERS) gave rise to satisfactory Raman spectra of the dye. Five different fractions were separated on the thin layer chromatography plate, and Raman and SERS measurements were carried out directly on each separated spot on the plate. As in the analysis of the raw product of the synthesis, only SERS gave high quality Raman spectra for the eluted spots. The assignment of the normal modes of mauveine was aided by performing density functional theory calculations.