Low Dimerizing Viologen Electrochromic Compounds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electrochromic devices using viologen-based compounds often experience undesirable color shifts due to dimer formation, which can be influenced by factors like temperature and cation radical concentration, affecting their performance and reliability.
Innovation Solution
The development of low dimerizing viologen-based electrochromic compounds, specifically those with structural features like 3,3' or 5,5' ethylene bridges, which reduce dimer formation rates, are used in electro-optic elements and devices, minimizing color shifts and improving performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional viologen-based compounds are used in electrochromic devices, then the devices can achieve electrochromic functionality, but undesirable color shifts occur due to dimer formation
Solution Approach 1:
The patent modifies the molecular structure of viologen compounds by introducing specific substituents (alkyl groups with 1-20 carbon atoms, hydroxyalkyl groups with 1-6 carbon atoms) at defined positions (R1, R3, R4) to change the physical and chemical parameters of the compound. These structural modifications reduce the tendency toward dimer formation while preserving electrochromic functionality, directly addressing the color stability issue.
Solution Approach 2:
The patent creates composite electrochromic compositions by combining modified viologen compounds with specific electrolytes (carbonate esters, carboxylic acid esters, cyclic carbonates, chain carbonates, sulfones, nitriles, amides, carboxylic acids, alcohols, water) in defined concentration ranges. This composite approach optimizes the electrochromic performance and minimizes dimer formation through synergistic interactions between components.
2Productivity
If viologen compounds are used in electrochromic devices, then coloring and clearing processes can occur, but dimer formation causes color variation that affects performance
Solution Approach 1:
The patent changes the molecular parameters of viologen compounds by introducing bulky alkyl and hydroxyalkyl substituents that sterically hinder dimer formation. This structural modification allows faster interconversion between oxidized and reduced states without the kinetic trap of dimer formation, thereby improving both coloring/clearing speed and color consistency simultaneously.
3Power
If temperature and cation radical concentration increase, then electrochromic response can be enhanced, but dimer formation rates increase causing color shifts
Solution Approach 1:
The patent modifies the thermal and electrochemical parameters of viologen compounds through structural substitution. The introduced alkyl and hydroxyalkyl groups alter the temperature dependence and cation radical stability, allowing the device to operate at higher temperatures and with higher cation radical concentrations without accelerating dimer formation, thus maintaining color stability under enhanced operating conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
These compounds decrease the rate of dimer formation, reducing color variation and enhancing the speed of coloring and clearing processes in electrochromic devices, leading to more stable and efficient performance.
Implementation Method 1
low dimerizing viologen-based electrochromic compounds
Implementation Method 2
electrochromic compound
Data Source
Figure 1
Figure 2A~2C
Figure 2D~2E
AI summary
A low dimerizing electrochromic compound for use in electrochromic mediums and electro-optic elements incorporating said electrochromic mediums is provided. The low dimerizing electrochromic compound is represented by Formula (I): (I) wherein each R1 is individually an alkyl, a hydroxyalkyl, or an alkyl substituted with at least one polymerizable functional group; each R2 is a hydrogen; each R3 is individually a hydrogen or an alkyl; and each R4 is individually a hydrogen, an alkyl, or a hydroxyalkyl; and X- is an anion.