A Comparison of Various FTIR and FT Raman Methods: Applications in the Reaction Optimization Stage of Combinatorial Chemistry

Abstract

Four different FTIR methodssingle-bead FTIR, beam condenser, macro attenuated total reflection (macro-ATR), and KBr pellet methodsand macro and single-bead FT Raman methods have been investigated, and the relative utility was compared for the analysis of resin-bound organic compounds and the monitoring of solid-phase organic reactions. Furthermore, the comparison includes two additional methods from the literature: diffuse reflectance infrared Fourier transform spectroscopy and photoacoustic spectroscopy. While all of these methods have some utility for solid-phase sample analysis, the relative merits of these methods vary particularly in such areas as the information content, spectral quality, sensitivity, speed, sample requirement, and the instrument cost. Both single-bead FTIR and beam condenser FTIR methods have been found to be superb methods in each of these aspects. In the following way, these methods meet many of the essential requirements for a thin layer chromatography (TLC) equivalent for soli...