Soluble molybdenum blues-"des Pudels Kern".

The earlier tremendous interest in molybdenum blue solutions-an enigma for generations of chemists-became even more pronounced when it turned out that the basic building units correspond to giant wheel-shaped clusters with nanostructured cavities, displaying exceptional aesthetic beauty. This discovery will stimulate new ideas in supramolecular chemistry, colloid chemistry, and materials science. The giant wheels represent nanosensors and nanoreactors, enabling the initiation of chemical processes at different positions, like a "structured landscape", and can even be used as robust synthons for the construction of compounds with typical solid-state structure, a situation comparable to crystal engineering.