Steering Polymer Growth by Molding Nanochannels: 1,5-Hexadiene Polymerization in High Silica Mordenite
Zeolites are known as scaffolds for the assembly of molecules via non-covalent interactions, yielding organized supramolecular materials. Yet their potential in driving the growth of low-dimensional systems requiring covalent bond formation is still uncharted. We incorporated 1,5-hexadiene in the channels of a high‑silica mordenite and analyzed the material by infrared spectroscopy, X-Ray powder diffraction, thermogravimetric and modeling techniques. Thanks to the few zeolite acid sites, 1,5‑hexadiene experiences a slow conversion to a polymer, mainly formed by cyclopentane units and featuring short side chains able to fit the channels. The shape-directing abilities of zeolite framework play a two-fold role, involving first the organization of the monomers inside the void-space and then the linear growth of the chain, dictated by the channel geometry. These findings highlight the molding action of zeolites in directing transformations of covalent bonds under ambient conditions and may provide insights for obtaining confined polymers with intriguing perspective applications.