Herein, we present the synthesis of a new ammonia oxidation catalyst [Ru(bpy-NMe2)(tpada)(Cl)](PF6) (1), with an adamantane binding group that can form a catalytically active HG complex on an electrode surface. Guest 1 was synthesized in a two-step reaction with the newly designed terpyridine-adamantyl (tpada) ligand (Schemes S1-2, Figures ), RuCl3 and 4,4'-bis(dimethylamino)-2,2'-bipyridine (bpy-NMe2) (Scheme S3, Figures ). The related adamantane-containing complex [Ru(bpy)(tpada)-(Cl)](PF6) (3) (Scheme S4, Figures ) with unsubstituted bpy instead of bpy-NMe2 exhibited a later onset potential for ammonia oxidation and was therefore not investigated further. :3) at 298 K with a constant host concentration of 0.001 M. The proton assignment of the host was done according to literature. The hydroxy units are not visible due to the fast exchange with D2O. The guest ratio is increased from 0 to 9 relative to the host concentration (from bottom to top). The binding constants were obtained using BindFit. With a cavity size of β-CD of 0.65 nm and a length of 0.78 nm, the smaller adamantyl guest can be bound more easily than the larger naphthyl guest. The binding of both guests 1 and 2 to β-CD in a dmso-d6: D2O (7:3) solution was monitored with 1 H NMR spectroscopy, and titration studies (Figure ) used to determine the solutionphase binding-constant. The binding behavior of both guests was compared by fitting the chemical shift change of the host protons and the G/H ratio with BindFit (Figures ). A more pronounced peak shift of the cyclodextrin protons assigned to protons b (Figure ) was observed when titrating guest 1 in comparison to guest 2, which implies a stronger interaction of the adamantane backbone with the host. We found a binding constant of K11= 492 ± 21 M -1 for the 1:1 inclusion complex of guest 1 with the β-CD host, which is almost three times higher than the one obtained for guest 2 (K11= 177 ± 8 M -1 ). These results suggest that the newly designed HG system could show higher stability during catalysis if the strong binding of the guest is transferred to the electrode surface.