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.