Interactions in liquid mixtures of formamide isotopomers studied by Raman spectroscopy

This is the authors' abstract. We don't add key points for this paper.

Recently, anomalies concerning both intensities and peak positions of Raman bands in the carbonyl stretching region of liquid mixtures of different isotopomers of formamide were reported. More detailed investigations have now been performed for liquid mixtures of HCONH2 and H13CONH2, and Raman spectra of mixtures of DCONH2 and DCOND2 in the carbonyl stretching region are presented. In the system DCONH2‐DCOND2, collapse of the isotropic carbonyl bands was observed in the mixtures as previously reported for HCONH2‐HCOND2 and HCOND2‐DCOND2. The system HCONH2—H13CONH2 shows anomalous intensities compared with those expected for simple binary mixtures. However, this system does not show collapsing carbonyl bands in the isotopomeric mixtures. The phenomenon of collapsing bands can be explained in terms of a model known as mutual entrainment.