Single-ion magnets (SIMs) are potential building blocks of novel quantum computing devices. Unique magnetic properties of SIMs require effective separation of magnetic ions and can be tuned by even slight changes in their coordination sphere geometry. We show that an additional level of tailorability in the design of SIMs can be achieved by organizing magnetic ions into supramolecular architectures, resulting in gaining control over magnetic ion packing. Here, γ-cyclodextrin was used to template magnetic Co(II) and nonmagnetic auxiliary Li(+) ions to form a heterometallic {Co, Li, Li}4 ring. In the sandwich-type complex [(γ-CD)2Co4Li8(H2O)12] spatially separated Co(II) ions are prevented from superexchange magnetic coupling. Ac/dc magnetic and EPR studies demonstrated that individual Co(II) ions with positive zero-field splitting exhibit field-induced slow magnetic relaxation consistent with the SIMs' behavior, which is exceptional in complexes with easy-plane magnetic anisotropy.

Mechanochemistry has recently emerged as an environmentally friendly solventless synthesis method enabling a variety of transformations including those impracticable in solution. However, its application in the synthesis of well-defined nanomaterials remains very limited. Here, we report a new bottom-up mechanochemical strategy to rapid mild-conditions synthesis of organic ligand-coated ZnO nanocrystals (NCs) and their further host-guest modification with β-cyclodextrin (β-CD) leading to water-soluble amide-β-CD-coated ZnO NCs. The transformations can be achieved by either one-pot sequential or one-step three-component process. The developed bottom-up methodology is based on employing oxo-zinc benzamidate, [Zn4 (μ4 -O)(NHOCPh)6 ], as a predesigned molecular precursor undergoing mild solid-state transformation to ZnO NCs in the presence of water in a rapid, clean and sustainable process.

Urea and its derivatives, due to their unusual versatility of coordination modes to metal centers and the presence of multiple hydrogen-bond donor sites, are widely utilized as neutral or monoanionic ligands in coordination and bioinorganic chemistry and as building units of bioinspired materials. However, metal complexes with ureate ligands have essentially not been applied as precursors of hybrid organic–inorganic nanomaterials. We report on the synthesis and structure characterization of two novel organozinc ureate complexes incorporating N-phenylureate or N,N′-dicyclohexylureate ligands, the latter being the first reported complex with the μ3-μ2(O):κ1(N) ureate coordination mode. These findings not only expand the horizon of urea–zinc chemistry but also pave the way for efficient bottom-up mechanochemical synthesis of sub-10 nm diameter zinc oxide nanocrystals (ZnO NCs) coated by the ureate ligands. We explored the NC formation triggered by mechanical force from both a well-defined monocrystalline precursor and an insoluble hard-to-process amorphous organozinc precursor. Moreover, the organic shell of the N-phenylureate-coated ZnO NCs was modified via a facile, fast, and solventless host–guest complexation with β-cyclodextrin using a mechanochemical approach, which afforded water-soluble ZnO NCs. The reported procedure is the first example of rapid and sustainable mechanochemical synthesis of hybrid nanomaterials from organometallic precursors.