Potentials of variable–variable and sample–sample, generalized and statistical, two-dimensional correlation spectroscopies in investigations of chemical reactions

Generalized and statistical variable–variable (VV) and sample–sample (SS) two-dimensional (2D) correlation spectroscopies are used to investigate a three-band spectral model that represents a simple consecutive chemical reaction. Generalized and comprehensive linear algebra basis, which is essential for the analysis of three-component systems by 2D correlation, is provided. It is found from the analysis of slice spectra of synchronous and asynchronous VV correlation maps of the model that the spectral and concentration influences of an intermediate can be identified and related to the real characteristics of the intermediate. 2D correlation spectroscopy may be effectively employed to give a semiquantitative portrayal of a chemical reaction. The results of statistical 2D correlation spectroscopy are not directly related to the bands or concentration profiles, but are concerned with simple trends in intensity changes in the spectra. It seems that for all consecutive reactions where the mass of the system is entirely preserved, SS correlation maps may be the same, independent of spectroscopic techniques for monitoring reactions. If this is the case, the results of the present study offer a prospect for automatic determination of reaction constants in successive reactions by the means of 2D correlation spectroscopy.