Delayed Fluorescent Compound with Asymmetric Donor Substituents
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Solution Overview
Problem
Existing light-emitting compounds, such as 4CzIPN, do not have an optimal configuration for maximizing emission efficiency, limiting the potential for further improvement in light emission efficiency in organic electroluminescent devices.
Innovation Solution
A compound is developed with donor and acceptor groups bonded to a core aromatic ring, where the donor groups differ in substituent conditions such as number, substitution sites, and configuration, enhancing emission characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a delayed fluorescent material with donor and acceptor groups is used to improve light emission efficiency, then the emission efficiency increases, but the structural configuration becomes complex and requires optimization of multiple parameters
Solution Approach 1:
The patent applies parameter changes by systematically varying the substituent conditions of donor groups (number of substituents, substitution sites, and configuration) bonded to the core aromatic ring. This allows optimization of the compound's emission characteristics while maintaining the delayed fluorescent mechanism, thereby improving light emission efficiency through controlled structural modifications.
Solution Approach 2:
The patent employs composite material design by combining donor groups with different substituent configurations with acceptor groups on a core aromatic ring. This creates a composite molecular structure that leverages the synergistic effects of different functional groups to achieve enhanced emission efficiency while managing structural complexity through modular design.
2Loss of energy
If the substituent conditions of donor groups are optimized to enhance emission characteristics, then the emission efficiency improves, but the difficulty of synthesizing the compound increases
Solution Approach 1:
The patent applies segmentation by dividing the complex donor group into modular units with specific substituent patterns. This allows the compound to be synthesized through stepwise reactions where each substituent can be introduced independently, simplifying the overall synthesis process while maintaining the optimized emission characteristics.
3Illumination intensity
If multiple different donor groups with varying substituent conditions are used, then the emission characteristics are enhanced, but the manufacturing precision requirements increase
Solution Approach 1:
The patent applies local quality by assigning specific substituent conditions to specific positions on the donor groups bonded to the core aromatic ring. Each substituent configuration is optimized for its local position to maximize emission characteristics, while the overall molecular structure maintains sufficient symmetry and regularity to facilitate precise manufacturing.
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 new compound achieves significantly higher emission efficiency in light-emitting devices compared to existing materials.
Implementation Method 1
A delayed fluorescent material is a compound which, in an excited state, after having undergone reverse intersystem crossing from an excited triplet state to an excited singlet state, emits fluorescence when returning back from the excited singlet state to a ground state thereof
Implementation Method 2
emits fluorescence when returning back from the excited singlet state to a ground state thereof
Data Source
AI summary
Using a compound represented by a general formula (A)m-L-(D)n, a light-emitting device having a high emission efficiency can be provided. L is an (m+n)-valent aromatic linking group; A is a group having a positive Hammett's σp value; D is a group having a negative Hammett's σp value; m is an integer of 1 or more; n is an integer of 2 or more. Two of plural D's differ in point of the substituent condition at specific aromatic rings.