The manuscript reports the synthesis of a series viologen based ionic polymer for EC application. The authors successfully addressed two challenges: 1) development of a simple and efficient approach to prepare CHO-functionalized N-arylated viologens. 2) fabrication of solution processible polymers for electrochromic applications. These two challenges are rarely addressed in previous literature. This class of building blocks is highly valuable, and would definitely broaden the scope of viologen-based functional materials for applications in diverse areas. The work is of high quality and novelty. Therefore, I strongly recommend without any reservation for publication in Chem. Sci. after some minor revision.

1) The electrochemistry of the electrochromic film was carried out in 0.1 M aqueous LiCl electrolyte. In many previous paper, organic electrolyte solution, such as LiClO4/propylene carbonate (PC), is commonly used. Does the author study the effect of the electrolyte systems on the electrochemistry?

2) The author proposed the formation of oligomers or molecular cage under low concentration, based on the sharp NMR signal. It would be interesting to get X-ray crystal structures to confirm it.

3) Could these ionic polymers be characterized by GPC?

4) It is typically difficult to characterize BET based on film. It would be better to give more details how to collect the samples for the measurement.

5) The authors are recommended to introduce a latest review article in the revised manuscript (https://doi.org/10.1016/j.jechem.2024.02.027).

I appreciate the revisions made by the authors, this manuscript can be accepted now.