Crystalline copper compound gets knotted

Crystalline materials are usually brittle and flexibility in single crystals is not a renowned property of salts and coordination complexes. Needless, to say this limits their applications to stiff systems whereas electronics and optics that are flexible could open up wearables and many other fields if only chemists could somehow make these compounds bend over backwards. Now, researchers in Australia have spotted a potentially useful trait of a familiar compound – copper(II) acetylacetonate or [Cu(acac)₂] to bench chemists everywhere. The team has shown that single crystals of this well-known coordination compound can be reversibly tied in knots.