Controlled Fabrication and Characterization of Coronene Diimide‐Based Insoluble Thin Films Produced by Photoinduced Cyclization

• Published in: ChemPlusChem (Weinheim, Germany) Germany), 2021-06, Vol.86 (6), p.852-857
• Main Authors: Ogawa, Tomoya, Kuzuhara, Daiki
• Format: Article
• Language: English
• Subjects: multi-layer thin films; organic devices; organic thin-film transistors; perylene diimide; photocyclization reaction
• ISSN: 2192-6506; 2192-6506
• DOI: 10.1002/cplu.202100131

An insoluble thin film of a coronene diimide (CDI) derivative was fabricated from a soluble precursor of perylene diimide (PDI) by photoirradiation. We prepared a 1,7‐diarylated PDI (TP‐PDI) that can be converted into a coronene diimide (TP‐CDI) derivative via a Scholl‐type photocyclization reaction. This reaction was accompanied by structural changes from a twisted structure to a π‐extended planar molecule. It was found that this photoconversion reaction occurs for both solution‐based and thin‐film‐based reactants investigated by the changes of UV‐vis absorption spectra and 1H NMR spectra. The photocyclization reactions were found to proceed smoothly in polar solvents. In the thin‐film state, the solvent vapor annealing method is a key process for achieving photoconversion reaction. Additionally, the fabrication of multi‐layered thin films was achieved without undesirable dissolution of the underlying layers because of different solubilities of TP‐PDI and TP‐CDI. The light on organic devices: 1,7‐Diarylated PDI (TP‐PDI) can be converted into a coronene diimide (TP‐CDI) by a Scholl‐type photocyclization reaction. This photoconversion reaction proceeds in both solution and thin films. The solvent vapor annealing method is the key process for achieving the photoconversion reaction in thin films. Additionally, the fabrication of multilayered thin films using a deposition process was demonstrated.