New phosphorescent iridium(iii) dipyrrinato complexes: synthesis, emission properties and their deep red to near-infrared OLEDs

Hongyang Zhang, Haitao Wang, Kevin Tanner, Adrien Schlachter, Zhao Chen, Pierre D. Harvey, Shuming Chen, Wai Yeung Wong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

4 Citations (Scopus)

Abstract

A series of heteroleptic Ir(iii) complexes composed of two cyclometalated C^N ligands and one dipyrrinato ligand used as an ancillary ligand are synthesized and characterized. With the introduction of a fluorine atom, phenyl ring or diphenylamino group into both C^N ligands and by keeping the ancillary ligand unchanged, these Ir(iii) dipyrrinato phosphors do not show an obvious shift in their emission bands. They exhibit emissions extending well into the near-infrared region with an intense band located at around 685 nm in both photo- and electroluminescence spectra, and the deep red to near-infrared organic light emitting diodes (OLEDs) based on them afforded a maximum external quantum efficiency of 2.8%. Density functional theory (DFT) calculations show that both the electronic contributions on the lowest unoccupied molecular orbitals (LUMOs) and the highest energy semi-occupied molecular orbitals (HSOMOs) are mainly localized on the dipyrrinato ligand, indicating that the ancillary ligand, which remains unchanged in this series, exhibits a lower triplet state energy in the iridium phosphors than those involving the C^N ligands. Therefore a switch from “(C^N)2Ir” to dipyrrinato ligand-based emission is observed in these iridium(iii) complexes.

Original languageEnglish
Pages (from-to)10629-10639
Number of pages11
JournalDalton Transactions
Volume50
Issue number30
DOIs
Publication statusPublished - 14 Aug 2021

ASJC Scopus subject areas

  • Inorganic Chemistry

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