Geometry of Complex Molecular Motions of Guest Molecules in Polymers from Solid State 2H NMR

Nanoporous systems provide interesting possibilities to confine molecules to be used for specific functions, e.g., as switches, in sensorics, or in separation. Such behavior partially mimics biological systems, where enzymes with specific cavities exhibit exquisite binding discrimination and reactivity.1d,1e Recent advances in solid-state inclusion compounds produced an extraordinary variety of cavities that encapsulate guests through noncovalent forces and can be customized through molecular design to control their solid-state properties and guest reactivity. Crystalline polymers offer the additional advantage of processability and alignment due tomechanical forces. In this context, the nanoporous δ and ε crystalline phases of syndiotactic polystyrene (s-PS), obtained by guest removal with supercritical carbon dioxide from cocrystalline phase, offer promising applications in chemical separation (mainly air/water purification), in sensorics, and optical applications.