Investigation of phenyl and triphenylamine-based star-shaped viologens for electrochromic applications

Title : Investigation of phenyl and triphenylamine-based star-shaped viologens for electrochromic applications

Abstract:

The branched viologens (so-call star-shaped) are organic compounds derived from 1,1’-di(hydrocarbyl)-4,4’-bipyridinium salt, which contain three or more pyridine rings connected to a central core. The implementation of the branched unit instead of linear one results in obtaining star-shaped compound. These viologens have attracted a greater interest in recent years due to their clearly different properties compared to the linear viologens. Switching between different redox states results in a very distinct color changes and this is the reason why they are intensively studied in terms of their electrochromic applications.[1] It is expected that the branched compounds containing three N-substituted pyridine rings will undergo more oxidation/reduction processes and thus exhibit more colors during electrochemical oxidation/reduction.[2]

In our research the two star-shaped viologens containing 1,3,5-substituted phenyl group and triphenylamine moieties with n-hexyl chains were synthesized and characterized using spectroscopic methods (¹H NMR, ¹³C NMR, HR-ESI-MS). The compounds are N-substituted with n-hexyl chains what increases their solubility in organic solvents. This allowed for investigation solvatochromic properties of the triphenylamine-based viologen. The electrochemical and spectroelectrochemical measurements of the branched compounds were also investigated. Both star-shaped viologens indicate promising optical properties and these molecules could be used as the active materials in electrochromic applications.[3]

Audience take-away:

• Participants will gain knowledge about viologens and their unique possibilities of applications in modern technology.
• The presentation will provided information about electrochemical and spectrochemical measurements to characterize viologens in that other scientists could use the methods to expand their research.
• The audience will get to know the two novel star-shaped viologens containing 1,3,5-substituted phenyl group and triphenylamine moieties with n-hexyl chains as a active materials electrochromic applications.

Biography:

Mr. Radosław Banasz studied Chemistry at the Adam Mickiewicz University in Poznan, Poland and graduated as MSc in 2021. He joined the research group of Prof. Monika Wałęsa-Chorab in 2017 at the same Institution. Mr. Banasz is a PhD student in the discipline of Chemical Science. He conducts research which is supported by Ministry of Science and Higher Education, Republic of Poland under the “Diamond Grant” program no. DI2019/0164/49. His currently research focus on synthesis and characterization of viologens as functional materials for applications in electrochromic devices. He is an author and co-author of 6 research articles in SCI(E) journals.