Reducing undesired solubility of squarephaneic tetraimide for use as an organic battery electrode material
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Author(s)
Type
Journal Article
Abstract
Locally aromatic alkyl-N-substituted squarephaneic tetraimide (SqTI) conjugated macrocycles are four-electron reducible, owing to global aromaticity and presumed global Baird aromaticity of the dianion and tetraanion states, respectively. However, their good solubility inhibits their application as a battery electrode material. By applying sidechain removal as a strategy to reduce SqTI solubility, we report the development of its unsubstituted derivative SqTI-H, which was obtained directly from squarephaneic tetraanhydride by facile treatment with hexamethyldisilazane and MeOH. Compared to alkyl-N-substituted SqTI-Rs, SqTI-H exhibited further improved thermal stability and low neutral state solubility in most common organic solvents, owing to computationally demonstrated hydrogen-bonding capabilities emanating from each imide position on SqTI-H. Reversible solid state electrochemical reduction of SqTI-H to the globally aromatic dianion state was also observed at -1.25 V vs. Fc/Fc+, which could be further reduced in two stages. Preliminary testing of SqTI-H in composite electrodes for lithium-organic half cells uncovered imperfect cycling performance, which may be explained by persistent solubility of reduced states, necessitating further optimisation of electrode fabrication procedures to attain maximum performance.
Date Issued
2024-03-01
Date Acceptance
2023-08-17
Citation
Faraday Discussions, 2024, 250, pp.129-144
ISSN
1359-6640
Publisher
Royal Society of Chemistry
Start Page
129
End Page
144
Journal / Book Title
Faraday Discussions
Volume
250
Copyright Statement
This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
License URL
Identifier
http://dx.doi.org/10.1039/d3fd00145h
Publication Status
Published
Date Publish Online
2023-08-17