The Raman spectra of H-2 and D-2 adsorbed on metal-organic framework-5 at various pressures (H-2: 12.8 and 30.3 bar; D-2: 2.2-24.5 bar) and temperatures (H,: 298 K; D,: 40-300 K) have been recorded. The shifts observed in the vibrational modes of the gases indicate that physisorption is responsible for the attractive interactions between the gas and the framework; these interactions are larger with respect to those detected for carbon materials. (c) 2005 Elsevier B.V. All rights reserved.