We seek to develop new materials for sensing and removal of toxic gases (esp., SO2) and request 2 days on POLARIS to study the structural binding details and dielectric data simultaneously as SO2 is adsorbed in two stable MOFs. We will use our microwave frequency resonator sample environment and gas delivery system, which has been used previously with the POLARIS beamline. Microwave dielectric measurements, when correlated with other characterisation techniques offer an easy and non-destructive method for interrogating polar molecule sequestering as well as providing a deeper understanding of mechanisms for gas sequestration. This proposal will allow us to perform correlation studies that will enable the determination of the structural origins of changes in dielectric behaviour as SO2 molecules are bound within the MOF structure, insights into the mechanism of sequestration.