[Ru(TPT)2]2+ undergoes nucleophilic attack at the ligand in aqueous solutions of HO-. The reaction is reversible and the equilibrium can be followed spectrophotometrically. In acid solution, the free nitrogen atoms of the uncoordinated pyridine residues are protonated to form a new species. Two reactions of [Fe(TPT)2]2+ take place in H2O over extended periods. The first is the well-known dissociative process, but the second appears to involve reaction at the ligand. The results are used to reinterpret some of the chemistry of complexes of TPT and related ligands.