The Borromean ring, an icon of Nordic and Christian traditions, has been self-assembled at the molecular scale level for the first time. The new molecule, composed of three interlocking rings, provides another new component for future nano-devices.For decades, chemists have been creating molecules with ever more complicated shapes. Two rings had already been made to interlock, by creating one ring and then building a second around it. A five-link chain has also been strung together.But the Borromean ring - three rings entwined such that breaking one separates the other two - has proved elusive. It has been moulded in DNA, but only in a very wound-up form."The molecular Borromean rings became a kind of Holy Grail in recent years,” says Fraser Stoddart, director of the California NanoSystems Institute in Los Angeles, where the molecular rings were created. “There was a bit of a friendly race going on to see who would get there first.”