Metal organic frameworks (MOFs) are hybrid and crystalline materials composed of metal centers connected by organic ligands. The resulting 3D frameworks exhibit ultrahigh porosity and large surface areas that can be modulated for specific applications due to the wide availability of metalligand combinations. For this reason, MOFs have been extensively studied for applications in many different fields of science such as catalysis, drug delivery or gas adsorption, separation, 8,9 sensing 4,10-12 and storage, among others. One of the applications that has attracted the most attention in recent years is the capture of polluting gases emitted from anthropogenic sources. Special attention has been paid to carbon dioxide due to its strong impact on the greenhouse effect. Other gases, like carbon monoxide, can also play an important role in climate change and the development of capture strategies is interesting not just for environmental concerns but also for the possibility of reusing them in other industrial chemical processes. Hofmann-like clathrates with general formula Fe(pz)[M(CN)4] (pz = pyrazine, M = Ni, Pd, Pt) are a versatile class of MOFs with octahedrally coordinated Fe(II) centers connected by cyanide ligands, CN -, to a square-planar openmetal site, M(II). The resulting Fe[M II (CN)4]∞ layers are pillared by bidentated aromatic ligands resulting in threedimensional networks. These materials are interesting for gas capture applications due to the combination of openmetal M(II) sites and bistable Fe(II) spin-crossover centers. These can undergo a spin-state switch under the influence of external stimuli such as temperature, pressure, light or incorporation of guest molecules. The presence of unsaturated metal centers can, potentially, enhance the adsorption capacity, whereas their bistability can be used for sensing applications. Several studies of gas adsorption have been published since their discovery in 2001, including the interplay between spin-crossover and guest molecules. Recently, the member of the series Fe(pz)[M(CN)4] with M = Pt(II) has shown a significant higher CO2 and CO uptake capacities compared to other MOFs with larger surface areas. In this work, we focus our interest in these Hofmann-like clathrates upon CO2 and CO loading. We report a detailed study of gas adsorption mechanism of CO and CO2 in Fe(pz)[Pt(CN)4] in the low-spin state by means of neutron scattering techniques and density-functional theory calculations. We identified the two adsorption sites, on top of the open-metal site and between the pyrazine rings, and the most stable orientational configuration of the guest molecules and the pyrazine ligands of the framework was determined. The inelastic neutron scattering results assisted by DFT calculations, show signatures of a hindrance of the pyrazine libration and the out-of-plane movement of cyanide ligands when the gas is adsorbed. Together with the computed binding energy and a molecular orbital analysis, these results agree with a physisorption mechanism for both gases.