We report the covalent post-assembly modification of kinetically metastable amine-bearing (Fe2L3)-L-II triple helicates via acylation and azidation. Covalent modification of the metastable helicates prevented their reorganization to the thermodynamically favored (Fe4L4)-L-II tetrahedral cages, thus trapping the system at the non-equilibrium helicate structure. This functionalization strategy also conveniently provides access to a higher-order tris(porphyrinatoruthenium) helicate complex that would be difficult to prepare by de novo ligand synthesis.