Moving-window two-dimensional correlation spectroscopy and perturbation-correlation moving-window two-dimensional correlation spectroscopy

Numerical computations and practical applications of moving-window two-dimensional (MW2D) correlation spectroscopy and perturbation-correlation moving window two-dimensional (PCMW2D) correlation spectroscopy are reviewed. A series of spectra obtained under a certain external perturbation, e.g., temperature dependent infrared spectra, time-resolved near-infrared spectra, etc., is used for the analyses. Two-dimensional correlation map spread in a plane between spectral variable axis and perturbation variable axis is obtained by the computation. These methods therefore have become one of promising techniques to find informative bands in the spectral variable direction as well as informative perturbation points such as phase transition temperature in the perturbation variable direction.