Raman investigation of 1,4-cyclohexadiene in the liquid and solid state

Abstract We have obtained the room temperature Raman spectra of liquid 1,4-cyclohexadiene and its isotopic analogs: C 6 H 7 D, gem -C 6 H 6 D 2 , trans -C 6 H 6 D 2 and C 6 H 4 D 4 . Additionally, we have measured the Raman spectra of 1,4-cyclohexadiene as a function of temperature from 5 to 300 K. The conformation of 1,4-cyclohexadiene is found to be very likely planar in the solid state. The solid—solid phase transition at 192 K reported by calorimetric measurements has been observed and is discussed qualitatively.