The synthesis and characterization of near-infrared absorbing, electrochromic polyimides containing a dinuclear ruthenium complex in the polymer mainchain

A redox-active, near-infrared absorbing dinuclear ruthenium complex was incorporated into the mainchain of polyimides using a two-stage polymerization method. The polyimides show high thermal stability with a decomposition temperature range from 172 to 248 °C and glass transition temperature of 97–180 °C, depending on the dianhydride monomer used. The polyimides are redox active, electrochromic at 1600 nm with the ruthenium complex being in the mixed-valence state and fluorescent at 790 nm.