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Mixed annihilation electrogenerated chemiluminescence of iridium(iii) complexes

Version 3 2024-09-23, 12:19
Version 2 2024-06-03, 07:11
Version 1 2018-07-12, 10:12
journal contribution
posted on 2018-07-28, 00:00 authored by Lachlan SoulsbyLachlan Soulsby, David HayneDavid Hayne, Egan DoevenEgan Doeven, David J D Wilson, Johnny Agugiaro, Tim ConnellTim Connell, Lifen Chen, Conor F Hogan, Emily KerrEmily Kerr, Jacqui AdcockJacqui Adcock, Paul S Donnelly, Jonathan M White, Paul FrancisPaul Francis
Previously reported annihilation ECL of mixtures of metal complexes have generally comprised Ir(ppy)3 or a close analogue as a higher energy donor/emitter (green/blue light) and [Ru(bpy)3]2+ or its derivative as a lower energy acceptor/emitter (red light). In contrast, here we examine Ir(ppy)3 as the lower energy acceptor/emitter, by combining it with a second Ir(iii) complex: [Ir(df-ppy)2(ptb)]+ (where ptb = 1-benzyl-1,2,3-triazol-4-ylpyridine). The application of potentials sufficient to attain the first single-electron oxidation and reduction products can be exploited to detect Ir(ppy)3 at orders of magnitude lower concentration, or enhance its maximum emission intensity at high concentration far beyond that achievable through conventional annihilation ECL of Ir(ppy)3 involving comproportionation. Moreover, under certain conditions, the colour of the emission can be selected through the applied electrochemical potentials. We have also prepared a novel Ir(iii) complex with a sufficiently low reduction potential that the reaction between its reduced form and Ir(ppy)3+ cannot populate the excited state of either luminophore. This enabled, for the first time, the exclusive formation of either excited state through the application of higher cathodic or anodic potentials, but in both cases, the ECL was greatly diminished by parasitic dark reactions.

History

Journal

Physical chemistry chemical physics

Volume

20

Issue

28

Pagination

18995 - 19006

Publisher

Royal Society of Chemistry

Location

Cambridge, Eng.

eISSN

1463-9084

Language

eng

Publication classification

C1 Refereed article in a scholarly journal

Copyright notice

2018, the Owner Societies