The inclusion of (TBA)(2)Mo6Br8F6 (TBA = tetrabutylammonium) containing [Mo6Br8F6](2-) cluster units within the pores of the mesoporous chromium carboxylate MIL-101 (MIL stand for Materials from Institut Lavoisier) has been studied. X-ray powder diffraction, thermal analysis, elemental analysis, solid-state NMR. and infrared spectroscopy have evidenced the successful loading of the cluster. In a second step, the hydrogen sorption properties of the model cluster loaded metal organic framework (MOF) system have been analyzed and compared to those of the pure MOF sample, through a combination of adsorption isotherms (77 K, room temperature), thermal desorption spectroscopy, and calorimetry (calculated and experimental) in order to evaluate the hydrogen storage efficiency of the cluster loading.