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., Schürmann, C. J., Ito, S., Yamano, A., Argent, S. P., George, M. W., & 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: Nature Publishing Group
• 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.