Analysis of the FTIR spectra of the impregnated carvacrol@MIL-100(Fe) material (Figures and) revealed the appearance of the most remarkable bands of carvacrol (νO-H 3361 cm -1 and νC-H 2958 and 2869 cm -1 ) in addition to the typical bands corresponding to Fe III trimesate MOF (νC=O 1620, 1570, 1445, and 1370 cm -1 ). Moreover, it can be noticed that the νas(Fe3O) vibration at 618 cm -1 , characteristic of the Fe III oxo-trimeric core in MIL-100(Fe), appears shifted to 628 cm -1 in the composite material. This suggests an effective interaction between the carvacrol molecules and the accessible Fe III sites, as previously described for the binding of different molecules. In an attempt to further investigate the host-guest interaction, the biocomposite and the control empty material were exposed to thermal treatment under vacuum for 2 hours.