High Molar Mass [n]Cycloparaphenylene Conjugated Polymers and Copolymers with Improved Electron Delocalization

This work reports the synthesis of [ n ]cycloparaphenylene ([ n ]CPP) conjugated polymers and copolymers based on poly( p -phenylene vinylene) (PPV). We utilize the Gilch polymerization to generate high molar mass [ n ]CPP conjugated polymers for the first time, demonstrating that a 2,5bis(chloromethyl)[8]CPP monomer is compatible with the polymerization method by observing the highly reactive p -biquinodimethane intermediate via in-situ NMR spectroscopy. Hindered by their complex synthesis and limited solubility at high [ n ]CPP content, we then synthesize a series of solution-processable [8]CPP-PPV-co-MEH-PPV copolymers. Photophysical experiments in both solution and as drop-cast thin films, in conjunction with computational analysis, allow for the evaluation of both the radial [ n ]CPP and linear PPV component as [n]CPP content is modulated. These findings introduce a new strategy for integrating the radially conjugated [ n ]CPP macrocycle into processable, high molar mass π-conjugated polymeric systems, towards enabling expanded molecular design in organic electronic materials.