This proposed study will investigate the interactions exhibited by some weakly scattering gas substrates (NOx and small hydrocarbons) at different loadings. We request 13 days on TOSCA to study the interaction of adsorbed gas molecules (NO2, NO, N2O, C2H2, C2H4, C2H6, C3H6 and C3H8) within two new porous MOF materials [NOTT-300(V) and NOTT-300(V,Al)]. These MOFs exhibit extremely high selectivity for unsaturated hydrocarbons and NOx at ambient conditions, with high uptake capacities, suggesting the presence of specific guest/host interaction. The proposed study aims to reveal the nature of these selective gas uptake properties by analysing the guest/host interaction.