Fig. 3. Sketch of the stepwise synthetic strategy used in this work to prepare the heterometallic, mixed-ligand cage: viz. combination of pre-formed fac-[Ru(L^a)₃]²⁺ (red), additional labile Cd²⁺ ions (blue), and free ligand (L^b, black) in a 4 : 12 : 12 ratio to give hexadecanuclear [Ru₄Cd₁₂(L^a)₁₂(L^b)]³²⁺ with L^a = L^ph and L^b = L^naph.