Zr12-propionate is similarly synthesized and purified as Zr12-acetate. We extended the synthetic strategy to longer carboxylic acid ligands (see Scheme 1), but the resulting clusters cannot be crystallized anymore and therefore other purification techniques are required. The Zr12-butanoate is washed overnight in acetonitrile, while Zr12-hexanoate, Zr6-methylbutyrate and Zr6-methylheptanoate clusters can be precipitated with acetonitrile and isolated by centrifugation. Dissolution in DCM and repeating the precipitation cycle twice, delivers the purified clusters. This type of purification is typical for colloidal nanocrystals, and thus reinforces the idea of fatty acid capped clusters as atomically precise models for nanocrystals. For the clusters with even longer ligands (octyl, decyl, dodecyl and oleyl chains), the first precipitation is performed with acetonitrile, while acetone is the preferred anti-solvent for the two consecutive steps to precipitate the clusters, and separate it from, e.g., the ester co-product. The physical appearance of the clusters ranges from semi-crystalline solids (acetate, propionate, methylbutanoate) to waxy solids (butanoate, hexanoate, decanoate, dodecanoate) or viscous oils (octanoate, oleate, methylheptanoate), see Figure .