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) correlat ion spectroscopy, sample-sample correlation spectroscopy, is proposed to ob tain the information about the species' perturbation-dependent dynamics. Th is is the first report of monitoring perturbation dynamics in the samples b y generalized 2D approach. After the rows and columns of the experimental m atrix are exchanged in a way that the spectral data set is arranged in rows . unlike the common case, the correlation between the concentrations of spe cies is calculated. The method has been applied to a model system consistin g of two bands with different degrees of overlapping. The concentration-dep endent dynamics of the components that give rise to the two bands has been successfully analyzed. Similarities, differences, and correspondences betwe en wavenumber - wavenumber correlation spectroscopy (existing generalized 2 D 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 irres pective of the ratio of the band intensities, as is revealed in the analysi s of highly overlapped infrared (IR) spectra in the region of 3300-2700 cm( -1) artificially synthesized from two polymer spectra.