A new possibility of the generalized two-dimensional correlation spectroscopy. 1. Sample-sample correlation spectroscopy

In this paper an extension of the generalized two-dimensional (2D) correlation spectroscopy, sample-sample correlation spectroscopy, is proposed to obtain the information about the species' perturbation-dependent dynamics. This is the first report of monitoring perturbation dynamics in the samples by generalized 2D approach. After the rows and columns of the experimental matrix are exchanged in a way that the spectral data set is arranged in rows. unlike the common case, the correlation between the concentrations of species is calculated. The method has been applied to a model system consisting of two bands with different degrees of overlapping. The concentration-dependent dynamics of the components that give rise to the two bands has been successfully analyzed. Similarities, differences, and correspondences between wavenumber - wavenumber correlation spectroscopy (existing generalized 2D correlation spectroscopy) and sample-sample correlation spectroscopy have been discussed. The pretreatments of mean normalization and mean centering seem to yield the best results. The application of the presently proposed sample-sample correlation spectroscopy gives correct results probably irrespective of the ratio of the band intensities, as is revealed in the analysis of highly overlapped infrared (IR) spectra in the region of 3300-2700 cm(-1) artificially synthesized from two polymer spectra.