Direct Arylation Polymerization of Degradable Imine-based Conjugated Polymers

The development and optimization of reliable polymerization methods are needed for the synthesis of degradable imine-based conjugated polymers, which are attractive materials for transient electronics. Direct arylation polymerization (DArP) has emerged as a sustainable and atom-economical synthetic method for the preparation of well-defined conjugated polymers. Compared to polymerization methods such as imine polycondensation or Stille cross-coupling polymerization which require monomer functionalization, direct arylation proceeds via C-H activation and thereby reduces synthetic complexities and toxic by-products. Here we report the first use of DArP for the synthesis of an imine-based indacenodithiophene (IDT) copolymer, p(IDT-TIT). Polymers prepared via DArP can result in branched or cross-linked polymer chains due to the reactivity of C-H bonds in the monomers. In this report, we demonstrate a systematic study focusing on the reaction conditions needed to prepare p(IDT-TIT) via DArP with tetramethylethylenediamine as a co-ligand. The degradable polymer is characterized via nuclear magnetic resonance spectroscopy, high-temperature gel permeation chromatography, and ultraviolet- visible-near-infrared spectroscopy. With the simplicity of monomer preparation and reaction conditions, we anticipate this efficient synthetic protocol will lead to higher synthetic adoption in the research community to aid the exploration of high-performance imine-based degradable materials.