Selective photoinduced charge separation in perylenediimide-pillar[5]arene rotaxanes

Pearce, Nicholas; Reynolds, Katherine E. A.; Kayal, Surajit; Sun, Xue Z.; Davies, E. Stephen; Malagreca, Ferdinando; Schürmann, Christian J.; Ito, Sho; Yamano, Akihito; Argent, Stephen P.; George, Michael W.; Champness, Neil R.

Abstract

The ability to control photoinduced charge transfer within molecules represents a major challenge requiring precise control of the relative positioning and orientation of donor and acceptor groups. Here we show that such photoinduced charge transfer processes within homo- and hetero-rotaxanes can be controlled through organisation of the components of the mechanically interlocked molecules, introducing alternative pathways for electron donation. Specifically, studies of two rotaxanes are described: a homo[3]rotaxane, built from a perylenediimide diimidazolium rod that threads two pillar[5]arene macrocycles, and a hetero[4]rotaxane in which an additional bis(1,5-naphtho)-38-crown-10 (BN38C10) macrocycle encircles the central perylenediimide. The two rotaxanes are characterised by a combination of techniques including electron diffraction crystallography in the case of the hetero[4]rotaxane. Cyclic voltammetry, spectroelectrochemistry, and EPR spectroscopyare employed to establish the behaviour of the redox states of both rotaxanes and these data are used to inform photophysical studies using time-resolved infra-red (TRIR) and transient absorption (TA) spectroscopies. The latter studies illustrate the formation of a symmetry-breaking charge-separated state in the case of the homo[3]rotaxane in which charge transfer between the pillar[5]arene and perylenediimide is observed involving only one of the two macrocyclic components. In the case of the hetero[4]rotaxane charge separation is observed involving only the BN38C10 macrocycle and the perylenediimide leaving the pillar[5]arene components unperturbed.

Citation

Pearce, N., Reynolds, K. E. A., Kayal, S., Sun, X. Z., Davies, E. S., Malagreca, F., …Champness, N. R. (2022). Selective photoinduced charge separation in perylenediimide-pillar[5]arene rotaxanes. Nature Communications, 13(1), Article 415. https://doi.org/10.1038/s41467-022-28022-3

• Journal Article Type: Article
• Acceptance Date: Dec 22, 2021
• Online Publication Date: Jan 20, 2022
• Publication Date: 2022
• Deposit Date: Jan 26, 2022
• Publicly Available Date: Jan 26, 2022
• Journal: Nature Communications
• Electronic ISSN: 2041-1723
• Publisher: Springer Science and Business Media LLC
• Peer Reviewed: Peer Reviewed
• Volume: 13
• Issue: 1
• Article Number: 415
• DOI: https://doi.org/10.1038/s41467-022-28022-3
• Keywords: General Physics and Astronomy; General Biochemistry, Genetics and Molecular Biology; General Chemistry
• Public URL: https://nottingham-repository.worktribe.com/output/7340526
• Publisher URL: https://www.nature.com/articles/s41467-022-28022-3
• Additional Information: Received: 18 October 2021; Accepted: 22 December 2021; First Online: 20 January 2022; : The authors declare no competing interests.