IR study on the intensity of ν1 of carbon disulfide

The IR intensity of ν₁ of carbon disulfide is reported in various states. The intensity increases with a decrease in temperature. Less than 10% of the observed intensity can be explained in terms of an electric field applied from an adjacent molecule. On the other hand, nearly half of the intensity is explained in terms of a vibrational coupling of ν₁ with ν₃ or ν₂, which is estimated from dimer models, on the assumption that the observed IR and Raman frequencies can be attributed to dimers.