Cyclic and topological polymers: Ongoing innovations and upcoming breakthroughs

The chain topology of polymer molecules arguably dictates their fundamental properties and functions. During the first two decades of this century a number of remarkable innovations have been observed in the field of polymer chemistry, to realize the precision designing of, in particular, a variety of cyclic and multicyclic polymer topologies. In this Perspective article, ongoing achievements and expectable breakthroughs in topological polymer chemistry are highlighted, by emphasizing the spectacular diversification of the choice of topologies in macromolecules beyond conventional linear or randomly branched forms.