Bis-triazolium perylene diimides: self-aggregation of twisted organic dyes

Hillis, Jamie Scott ORCID: 0009-0009-9529-3910 (2025). Bis-triazolium perylene diimides: self-aggregation of twisted organic dyes. University of Birmingham. M.Sc.

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Abstract

This thesis aims to showcase the potential of perylene diimide (PDI) aggregates for anion sensing. PDIs are notable class of organic dyes that are well suited for this type of study owing to their strong absorbance and fluorescence and their ability to form aggregates. In this thesis, charge-assisted hydrogen bonding is explored as a tool to control the interactions between PDIs and with anions, thereby impacting photophysical properties for optical anion sensing. Through this work it is shown that a novel bis-triazolium PDI forms aggregates. Using UV-vis spectroscopy the dimerization constant of the bis-triazolium, with PF_6^- as the counterion was found to be 1.25 ± 0.11 x 10^5 M^{-1} with a ΔG of dimerization of -29.1 kJ mol^{-1} when measured in chloroform. This value is in line with the aggregation constants of planar PDIs. This is significant since the bis-triazolium PDI possess a twisted perylene core and so would be expected to exhibit weak aggregation through π–π interactions, which highlights the potential role of charge-assisted hydrogen bonding. Additionally, the ability of this PDI to act as an anion sensor has been shown. With colour change visible with the naked eye when the iodide counter ion was exchanged for PF_6^-.

Type of Work:

Thesis (Masters by Research > M.Sc.)

Award Type:

Masters by Research > M.Sc.

Supervisor(s):