Raman spectroscopy of iodine molecules trapped in zeolite crystals

Abstract

We study the Raman spectroscopy of neutral iodine molecules confined in the channels of zeolite AlPO4-5 (AFI) and AlPO4-11 (AEL) crystals, which shows that the molecular vibration states are significantly modified by the confinements from the nanosize channels. An iodine molecule trapped in the AEL crystal has an effective internuclear potential close to an ideal harmonic oscillator, while that in the AFI crystal behaves similarly to that in free space. The results are further confirmed by measuring the temperature dependence of Raman spectral width.