Here is another molecule of the year, on a topic close to my heart, the catenane systems 1 and the trefoil knot 2 [cite]10.1126/science.aav5021[/cite] Such topology is closely inter-twinned with three dimensions (literally) and I always find that the flat pages of a journal are simply insufficient to do them justice. So I set about finding the 3D coordinates.
Carbon catenation Preparing interlocked rings and knots at the molecular scale traditionally relies on preorientation of the building blocks by nitrogen or oxygen substituents. Segawa et al. devised a distinct strategy to synthesize catenane and trefoil structures composed exclusively of carbon and hydrogen (see the Perspective by Van Raden and Jasti). They linked phenyl rings end to end into macrocycles that met in the middle at a silicon center. Excision of the silicon with fluoride then yielded the interlocked products. Science , this issue p. 272 ; see also p. 216