Studying the electrochemical properties of the HGCs on gold alone was not sufficient to obtain a clear picture of our catalytic system. Gold electrodes are known to undergo surface oxidation, which leads to the desorption of thiol-based adsorbates. Furthermore, the relatively low surface area and high background activities of gold for many catalytic processes make the analysis of catalytically active adsorbates very difficult. To address these issues and to compliment the array of available analytical techniques to study the surfacebound HGCs, metal oxide (MO) substrates were used, specifically indium tin oxide (ITO), zirconium dioxide (ZrO 2 ), and titanium dioxide (TiO 2 ). As these materials have similar properties in terms of surface-adsorption chemistry, the choice of substrate can be tailored to the application of analytical technique (ITO for electrochemical measurements, ZrO 2 for fluorescence and IR, and TiO 2 for solid state NMR). Furthermore, by preparing mesoporous layers of the MOs, higher surface areas are easily accessible, allowing for the use of further spectroscopic methods and simplifying the analysis of electrochemical data. To transfer the HGC chemistry from the gold to the MO substrates, two strategies were employed: direct introduction of multiple suitable binding groups, geminal bisphosphonates (BP), to the host scaffold (host 5, see Figure ) or pre-functionalization of the MO substrates with propiolic acid and subsequent thiol-yne click chemistry on the surface. Both strategies are schematically shown in Figure . The host molecules on MO substrates are slightly further away from the surface, and electrons are more localized and tightly bound in MOs. These factors may lead to decreased electronic coupling of the guests with the surface.