Abstract
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 (λmax=415 nm) to a yellow/green-emitting form (λmax=533 nm) on grinding with a pestle. The process is reversible.