Electrochromic Organic Compound Temperature-Dependent Absorption Spectrum

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Solution Overview

Problem

Electrochromic devices with bipyridine structures experience significant changes in absorption spectrum due to ambient temperature fluctuations, affecting their performance in applications like full-color displays and color filters.

Innovation Solution

An electrochromic organic compound with a specific structure, represented by general formulae (1) to (5), is used in the electrochromic device, which minimizes the change in absorption spectrum across different temperatures by suppressing the formation of associates and maintaining the monomer state, ensuring stable color performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a bipyridine derivative is used as an electrochromic material, then the device exhibits electrochromic phenomenon with color change, but the absorption spectrum changes significantly with ambient temperature

Engineering Contradiction:
Improveelectrochromic performanceVSAvoidabsorption spectrum
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent modifies the chemical structure of the bipyridine derivative by introducing specific substituents (formula (1)) to change the molecular parameters. This structural modification alters the electrochromic characteristics to reduce temperature dependence of the absorption spectrum while maintaining the electrochromic effect

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite electrochromic system by combining the modified bipyridine derivative with specific counterions (formula (2)) and encapsulating them in a polymer matrix (formula (3)). This composite structure provides thermal stability while maintaining electrochromic functionality

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If the absorption spectrum changes with temperature, then the electrochromic device can operate across temperature ranges, but the wavelength selectivity and color accuracy deteriorate

Engineering Contradiction:
Improvetemperature range operationVSAvoidwavelength selectivity
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent changes the molecular parameters of the bipyridine derivative through specific substitution patterns that broaden the operational temperature range while stabilizing the absorption characteristics. The modified structure maintains consistent wavelength selectivity across temperatures

Inventive Principle:
Principle #35Parameter changes

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

The electrochromic device exhibits a small change in absorption spectrum with temperature, enabling effective gradation control and reduced temperature dependence, thus maintaining consistent performance across varying ambient temperatures.

Implementation Method 1

An electrochromic phenomenon (EC phenomenon) is a phenomenon in which a reversible electrochemical reaction (oxidation-reduction reaction) induced upon application of voltage changes the light absorption range of a material and thus the material is colored or decolored.

Methodology Applied
Scientific EffectElectrochromism: Electrochromism

Implementation Method 2

a reversible electrochemical reaction (oxidation-reduction reaction) induced upon application of voltage changes the light absorption range of a material

Methodology Applied
Scientific EffectOxidation-reduction reaction: Redox Reactions

Data Source

PatentEP3428165B1Organic compound, electrochromic element, electrochromic device, optical filter, imaging device, lens unit, and window material
Publication Date: 2023.11.22 CANON KK
  • EP3428165B1 patent drawingFigure 1~2
  • EP3428165B1 patent drawingFigure 3(a)~3(b)
  • EP3428165B1 patent drawingFigure 4(a)~4(b)

AI summary

An organic compound is represented by general formula (1) below: where X1 and X2 are each independently selected from an alkyl group optionally having a substituent, an aryl group optionally having a substituent, and an aralkyl group optionally having a substituent; R11 to R16 are each independently selected from a hydrogen atom, an alkyl group optionally having a substituent, an alkoxy group optionally having a substituent, an aryl group optionally having a substituent, a heterocyclic group optionally having a substituent, and a halogen atom; R21 and R22 are each independently selected from a hydrogen atom, an alkyl group optionally having a substituent, an aryl group optionally having a substituent, and an aralkyl group optionally having a substituent; and A1- and A2- each independently represent a monovalent anion.