Cycloparaphenylene-Norbornene Monomers Afford Access to Carbon Nanohoop-Based Polymers

Abstract

Although impressive strides have been made toward achieving precise polymer architectures, the pursuit of monomers with diverse structures and functions remains a critical challenge for polymer design. Herein we disclose the first polymers constructed from cycloparaphenylenes (CPPs), a family of strained, pi-rich macrocycles. Poly-CPPs were prepared via ring-opening metathesis polymerization (ROMP) of benzonorbornene-embedded CPPs. The distinctive size-dependent properties of CPPs, including fluorescence and host-guest chemistry, are preserved in poly-CPPs, offering a means to capitalize on these properties in polymeric materials. Moreover, copolymerizing CPPs of two different diameters results in polymers with emergent photophysical and supramolecular properties not achievable with small molecule CPP units. This work sets the stage for CPP derivatives to serve as molecular building blocks for the next generation of functional polymers.