Solution-Processable Indenofluorene Donor-Acceptor Materials

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Donor-acceptor copolymers and small molecules face solubility issues, limiting their use in organic semiconducting applications due to the difficulty in synthesizing stable acceptor materials with solubilizing side chains, particularly for indenofluorene-based compounds which have promising electronic properties but are not widely used due to lack of solution-processable forms.

Innovation Solution

Modification of indenofluorene to form solution-processable acceptor compounds with solubilizing side chains, allowing for the formation of donor-acceptor copolymers and small molecules that can be used in organic semiconducting devices through coupling reactions, enabling the incorporation of indenofluorene into donor-acceptor materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If indenofluorene-based acceptor materials are synthesized for donor-acceptor copolymers, then electronic properties are improved, but solubility deteriorates

Engineering Contradiction:

Improveelectronic propertiesVSAvoidsolubility

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies local quality by introducing solubilizing side chains (alkyl, aryl, or heteroaryl groups) at specific positions on the indenofluorene core structure. These side chains are localized modifications that do not alter the core electronic properties of the indenofluorene acceptor but locally enhance solubility by adding bulky, hydrophobic groups that prevent excessive aggregation and improve processing in organic solvents.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent creates composite molecular structures by combining the indenofluorene acceptor core with electron donor moieties through covalent bonding to form donor-acceptor copolymers. This composite approach allows the material to exhibit both the desirable electronic properties of indenofluorene and the enhanced solubility provided by the donor units and their associated side chains.

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If solubilizing side chains are added to indenofluorene acceptor materials, then solubility is improved, but molecular complexity increases

Engineering Contradiction:

ImprovesolubilityVSAvoidmolecular complexity

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent segments the molecular structure into distinct functional modules: the indenofluorene acceptor core, the solubilizing side chains, and the electron donor moieties. This segmentation allows each component to be optimized independently - the core for electronic properties, the side chains for solubility, and the donor units for overall performance - while simplifying the synthesis pathway through modular assembly.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11370879B2Solution-processable indenofluorenes and methods to generate solution-processable indenofluorenes

Publication Date: 2022.06.28 INTERNATIONAL BUSINESS MACHINE CORPORATION

AI summary

In an embodiment, a composition is provided that includes an indenofluorene moiety; an alkyl radical, an aryl radical, or a heteroaryl radical chemically bound to the indenofluorene moiety; and an electron donor moiety bound to the indenofluorene moiety. In another embodiment, a device is provided that includes compositions described herein. In another embodiment, a method of forming a donor-acceptor small molecule or a donor-acceptor copolymer is provided that includes forming an indenofluorene moiety; forming an electron donor moiety; and reacting the indenofluorene moiety with the electron donor moiety in a cross-coupling reaction.