Two dimensional correlation Raman spectroscopy of perfluoropolyethers: Effect of peroxide groups

Perfluoropolyethers (PFPEs) have been investigated with Raman spectroscopy and density functional theory (DFT) calculations. The two dimensional correlation spectroscopy (2DCOS) approach has been applied to a set of PFPEs containing different concentrations of peroxide (OO) groups, thus allowing to evaluate the effect on the Raman spectra due to the presence of oxygen-oxygen bonds in the molecular structure. Careful analysis of the vibrational normal modes obtained with DFT calculations supports the detailed interpretation of the 2DCOS maps.