N , N , N -tridentate ligands coordinated to {Fe ₉ [M(CN) ₈ ] ₆ } (M = Re, W) induce the spin crossover on the external Fe sites of the cluster.

Square-planar [PtL₄]²⁻ (L = CN⁻, Cl⁻, Br⁻) anions are bound by π-acidic HAT(CN)₆ in solution and in the solid state to provide the basis for the first epitaxially grown anion–π crystalline composites.

Comprehensive studies on a concerted evolution of supramolecular interactions with multicomponent synthon reproduction provide a new tool to describe the trapping of flat [M(L)₄]²⁻ complexes within π-acidic cavities.

The emerging picturesque landscape of anion–π systems involving d-block metalates (cyanidometalates, halogenometalates, polyoxometalates) is presented based on a literature review and the personal research experience of the authors.