Innentitelbild: Massive Molecular Motion in Crystal Leads to an Unexpected Helical Covalent Polymer in a Solid‐state Polymerization (Angew. Chem. 9/2024)

An unexpected regiospecificity in topochemical ene–azide cycloaddition (TEAC) polymerization is reported by Kana M. Sureshan et al. in their Communication (e202316513). Based on Schmidt's postulates for topochemical reactions, both the reactivity and the structure of the product were predicted. While the monomer packing predicted a regiospecific reaction to form a 1,4-triazoline-linked polymer, surprisingly, it formed an unexpected 1,5-triazoline-linked polymer as a result of massive molecular motion before the TEAC reaction.