Concerning the spectral resolution enhancement of dynamic 2D-IR

Abstract A dynamic two-dimensional infrared (2D-IR) spectroscopic study of a hydrogen bonded polymer blend, poly(vinyl phenol) (PVPh)/poly(methyl acrylate) (PMA), in the C O stretching range was conducted to investigate one of the major features of this technique, i.e., spectral resolution enhancement. It was found that peak positions in the in-phase dynamic spectrum are different from the ones in the traditional Fourier transform infrared spectrometry (FT-IR) spectrum, which is a result of the subtraction procedure to obtain the former. In addition, the intensities of quadrature spectra are extremely low, which are easily affected by noise or interference, etc. Dynamic 2D-IR plots constructed from such dynamic spectra may produce new features that are actually artifacts. Thus, new features revealed by dynamic 2D-IR spectroscopy have to be interpreted with extreme care. To improve the quality of dynamic FT-IR and thereby the dynamic 2D-IR spectra, new strategies must be sought.