Jump to main content
Jump to site search

Issue 44, 2017
Previous Article Next Article

Cyclometalated Ir(III) complexes incorporating a photoactive anthracene-based ligand: syntheses, crystal structures and luminescence switching by light irradiation

Author affiliations

Abstract

Two cyclometalated complexes [Ir(dfppy)2(aip)](PF6) (1) and [Ir(ppy)2(aip)](PF6) (2) have been synthesized based on a photoactive anthracene-based ligand aip and cyclometalating ligands dfppyH and ppyH [dfppyH = (2-(2,4-difluorophenyl)-pyridine), ppyH = 2-phenyl-pyridine]. Their crystal structures indicate that an aip ligand uses its phenanthroline moiety to chelate an {Ir(dfppy)2}+ unit in 1, while an {Ir(ppy)2}+ unit in 2. In CH2Cl2, the anthracene units in aip, 1 and 2 underwent photo-oxidation upon irradiation with 365 nm light, forming species aip-O, 1-O and 2-O, respectively. This photo-oxidation resulted in luminescence switching, from a luminescent state (emission at 493 nm) to a non-luminescent state for aip, while from a non-luminescent state to a luminescent state with an emission at 519 nm for 1 and 578 nm for 2. Additionally, the luminescence of aip, 1-O and 2-O in CH2Cl2 can be modulated by using TFA to protonate the imidazole units and/or non-coordinated phenanthroline moiety in these compounds. Upon adding TFA, aip showed luminescence quenching, while species 1-O and 2-O revealed both luminescence-intensity decrease and emission-wavelength increase (Δλ = 9 nm for 1-O, and Δλ = 4 nm for 2-O). In this paper, we discuss the luminescence switching/modulation of aip, 1 and 2 by light-irradiation-induced photo-oxidation of their anthracene units and by TFA treatment.

Graphical abstract: Cyclometalated Ir(iii) complexes incorporating a photoactive anthracene-based ligand: syntheses, crystal structures and luminescence switching by light irradiation

Back to tab navigation

Supplementary files

Publication details

The article was received on 10 Aug 2017, accepted on 10 Oct 2017 and first published on 10 Oct 2017


Article type: Paper
DOI: 10.1039/C7DT02967E
Citation: Dalton Trans., 2017,46, 15443-15450
  •   Request permissions

    Cyclometalated Ir(III) complexes incorporating a photoactive anthracene-based ligand: syntheses, crystal structures and luminescence switching by light irradiation

    T. Gao, Z. Qu, Z. Tang and D. Cao, Dalton Trans., 2017, 46, 15443
    DOI: 10.1039/C7DT02967E

Search articles by author

Spotlight

Advertisements