Subtle Ligand Effects on the Formation and Behavior of Inorganic Guest−Organic Host Supramolecular System

An unusual “cationic inorganic guests within anionic organic hosts” system was constructed. For [Pd(ppma)2]@2H2tma·2H3tma (ppma = N-(pyridine-2-yl)pyrimidin-2-amine; H2tma = deprotonated trimesic acid; H3tma = trimesic acid), one ppma is dissociated in methanol, whereas for [Pd(dpa)2]@2H2tma·2H3tma·2H2O (dpa = di(pyridine-2-yl)amine), [Pd(dpa)2]2+ species is retained the same solution. Thus, subtle differences between ppma and dpa species exist both in solid state and in solution.