Science Daily — If you take a strip of paper, twist one end by 180° and then stick the two ends together to form a ring, the result is called a Möbius strip, a geometric shape with only one surface and one edge. […]
The Polish researchers have now synthesized a large molecular ring, which can be classified as an expanded porphyrin analogue, which can do what the glued-together paper strip cannot: Without having to break a single bond in the figure-eight-shaped ring system, it can switch back and forth between the Hückel and Möbius topologies.
Yeah ! Mais pas d’images😦