Tetradentate Platinum Complex for OLED Quantum Efficiency

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Solution Overview

Problem

Existing cyclometalated platinum (II) coordination complex phosphorescent materials suffer from low quantum efficiency and stability issues, making them unsuitable for commercial OLED production.

Innovation Solution

A tetradentate cyclometalated platinum (II) coordination complex based on carboxyl coordination and containing pyridyl acridine is developed, featuring a strong-field oxygen negative ion ligand for improved quantum efficiency and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bidentate ligands are used in cyclometalated platinum (II) coordination complexes, then the device structure is simple, but the ligands are easy to twist and vibrate resulting in low phosphorescence quantum efficiency

Engineering Contradiction:
Improvephosphorescence quantum efficiencyVSAvoidligand structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs a tetradentate ligand that combines multiple coordination sites (C^N^O^N) into a single integrated structure, creating a composite ligand system that provides both structural rigidity and strong coordination to the platinum center, thereby resolving the contradiction between simplicity and efficiency

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the key parameter of ligand denticity from bidentate to tetradentate, fundamentally altering the coordination mode and molecular rigidity to achieve high phosphorescence quantum efficiency while maintaining synthetic feasibility

Inventive Principle:
Principle #35Parameter changes

2Reliability

If tridentate ligands are used in cyclometalated platinum (II) coordination complexes, then the coordination capability is improved, but the electrochemical, photochemical, and thermal stability decrease due to the second ligand

Engineering Contradiction:
Improvecoordination capabilityVSAvoidelectrochemical, photochemical, and thermal stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The tetradentate ligand integrates multiple coordination functions (C^N^O^N) into a unified structure that provides strong overall coordination capability while the extended conjugated system and rigid framework enhance electrochemical, photochemical, and thermal stability simultaneously

Inventive Principle:
Principle #40Composite materials

3Reliability

If fluorescent materials are used in OLED devices, then the production process is simple, but the theoretical internal quantum efficiency is only 25% due to spin-statistics quantum theory

Engineering Contradiction:
Improveinternal quantum efficiencyVSAvoidmaterial system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the emission mechanism parameter from fluorescent to phosphorescent by incorporating heavy metal platinum, which activates spin-orbit coupling and enables triplet exciton utilization, thereby achieving theoretical internal quantum efficiency of up to 100%

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 tetradentate coordination complex achieves high quantum efficiency and photostability, making it an effective light-emitting material for OLED devices with improved performance and longevity.

Implementation Method 1

the strong spin-orbit coupling of heavy metal atoms can effectively promote the intersystem crossing of electrons from singlet to triplet

Methodology Applied
Scientific EffectSpin-orbit coupling:

Implementation Method 2

Professor Forrest of Princeton University discovered the phenomenon of phosphorescence electroluminescence of metal organic coordination complex molecular materials at room temperature

Methodology Applied
Scientific EffectPhosphorescence: Phosphorescence

Implementation Method 3

the coordination complex includes a tetradentate ligand containing a strong-field ligand of an oxygen negative ion, with strong coordination capability and high rigidity

Methodology Applied
Scientific EffectCoordination bonding: Chemical Bonding

Data Source

PatentEP4166561B1Quadridentate ring metal platinum (II) complex based on carboxyl coordination and comprising pyridyl acridine and use thereof
Publication Date: 2025.06.18 ZHEJIANG HUAXIAN PHOTOELECTRICITY TECHNOLOGY CO LTD
  • EP4166561B1 patent drawingFigure 1~2
  • EP4166561B1 patent drawingFigure 3~4
  • EP4166561B1 patent drawingFigure 5

AI summary

The present invention relates to the technical field of organic light-emitting materials, and provides a tetradentate cyclometalated platinum (II) coordination complex based on carboxyl coordination and containing pyridyl acridine, and use thereof. The tetradentate cyclometalated platinum (II) coordination complex has the structure of the general formula (I): In the present invention, the tetradentate cyclometalated platinum (II) coordination complex includes a tetradentate ligand containing a strong-field ligand of an oxygen negative ion, with strong coordination capability and high rigidity, which can improve the quantum efficiency and photostability.