Survival of the Fittest Nanojar: Stepwise Breakdown of Polydisperse Cu27-Cu31 Nanojar Mixtures into Monodisperse Cu27(CO3) and Cu31(SO4) Nanojars.

Nanojars are emerging as a class of anion sequestration agents of unparalleled efficiency. Dinegative oxoanions (e.g., carbonate, sulfate) template the formation of a series of homologous nanojars [Cu(OH)(pyrazolato)]n (n=27-31). Pyridine selectively transforms less stable, larger CO3(2-) nanojars (n=30, 31) into more stable, smaller ones (n=27, 29), but leaves all SO4(2-) nanojars (n=27-29, 31) intact. Ammonia, in turn, transforms all less stable nanojars into the most stable one and allows the isolation of pure [CO3(2-)⊂{Cu(OH)(pz)}27] and [SO4(2-)⊂{Cu(OH)(pz)}31]. A comprehensive picture of the solution and solid-state intricacies of nanojars was revealed by a combination of variable temperature NMR spectroscopy, tandem mass spectrometry, and X-ray crystallography.