Reinvestigation of the energy difference between anti and gauche ethanol in low-temperature argon and xenon matrices

► Matrix temperature of ethanol was varied at 15 ∼ 30 K in Ar and at 15 ∼ 55 K in Xe. ► Relative intensities of IR bands changed according to the Boltzmann distribution law. ► Energy difference was determined to be 29.4 ± 2.1 cm-1 in Ar and 20.0 ± 1.2 cm-1 in Xe. ► Interaction between a host ethanol molecule and guest noble-gas atoms was discussed.