Dynamic Crystals: Visually Detected Mechanochemical Changes in the Luminescence of Gold and Other Transition‐Metal Complexes

Back to the grindstone : Certain crystalline complexes of gold, platinum, and vanadium undergo dramatic changes in their luminescence or their color upon grinding. The picture shows the transformation of colorless crystals of (F₅C₆Au)₂(μ‐1,4‐CN₂C₆H₄)] powder from a blue‐emitting form (λ_max=415 nm) to a yellow/green‐emitting form (λ_max=533 nm) on grinding with a pestle. The process is reversible.