Two-dimensional correlation spectroscopy in analyzing the excitation wavelength dependence of ring breathing mode of 2,2′-dipyridylketone

Raman spectra have been recorded for 2,2′-dipyridylketone. Generalized two-dimensional correlation technique has been used to study the excitation wavelength dependent spectral intensity variation of this molecule. The correlation method yields that the apparent single peak corresponding to ring breathing mode is composed of multiple bands at 994 and 997 cm−1. The possible reason is suggested to explain the different types of intensity variation of these two bands with excitation frequencies.