Porous functional metal-organic framework (MOF) materials show great potential for high capacity gas storage and separation. We seek to develop new materials for carbon capture and acetylene storage and request 2 days on WISH to study the preferred binding sites and locations of adsorbed gas (CO2 and C2D2) molecules within two functionalised MOFs showing record-high adsorption capacities of CO2 and acetylene. In particular, the role of NO2 functional group in guest binding has never been studied before via diffraction. The high resolution, low background and large d-spacing capabilities of WISH make it ideal for analysing the precise locations of gas molecules (particularly for hydrocarbon molecules) within these porous MOF and to define the preferred orientations of molecules with respect to the binding sites (-NH2, -NO2 group) on the pore surface.