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.