Jump to main content
Jump to site search

Issue 29, 2018
Previous Article Next Article

Cyclometalated Ir(III) complexes [Ir(tpy)(bbibH2)Cl][PF6] and [Ir(tpy)(bmbib)Cl][PF6]: intramolecular π⋯π interactions leading to facile synthesis and enhanced luminescence

Author affiliations

Abstract

Cyclometalated Ir(III) complexes [Ir(tpy)(bbibH2)Cl][PF6] (1·PF6) and [Ir(tpy)(bmbib)Cl][PF6] (2·PF6), and the control complex [Ir(tpy)(mbib)Cl][PF6] (3·PF6) were synthesized at 135 °C for 10 hours for the former two complexes, while at 190 °C for 24 hours for the latter complex, in which the cyclometalated ligands bbibH2, bmbib and mbib incorporate one or two N-methylbenzoimidazole/benzimidazole units in order to explore the influence of the molecular structures of these complexes on their synthesis conditions and luminescence behaviors. The 1H NMR and crystal structure measurements indicate that both 1·PF6 and 2·PF6 contain intramolecular π⋯π stacking interactions between the non-coordinated N-methylbenzoimidazole/benzimidazole unit and the tpy ligand, but there are no such π⋯π interactions in 3·PF6. At room temperature, these complexes in CH3CN reveal an emission with a combination of 3MLCT and 3LC characteristics, occurring at 534 nm with a quantum yield Φ = 39.5% and a lifetime τ = 2.39 μs for 1·PF6, 536 nm with Φ = 66.4% and τ = 2.94 μs for 2·PF6, and 558 nm with Φ = 27.0% and τ = 1.75 μs for 3·PF6. Moreover, both 1·PF6 and 2·PF6 exhibit a TFA-induced luminescence decrease. Based on the comparison among 1·PF6, 2·PF6 and 3·PF6, we discuss the influence of intramolecular π⋯π interactions and Nimidazole–H/Nimidazole–CH3 units in 1·PF6 and 2·PF6 on their syntheses and luminescence.

Graphical abstract: Cyclometalated Ir(iii) complexes [Ir(tpy)(bbibH2)Cl][PF6] and [Ir(tpy)(bmbib)Cl][PF6]: intramolecular π⋯π interactions leading to facile synthesis and enhanced luminescence

Back to tab navigation

Supplementary files

Publication details

The article was received on 12 May 2018, accepted on 28 Jun 2018 and first published on 29 Jun 2018


Article type: Paper
DOI: 10.1039/C8DT01922C
Citation: Dalton Trans., 2018,47, 9779-9786
  •   Request permissions

    Cyclometalated Ir(III) complexes [Ir(tpy)(bbibH2)Cl][PF6] and [Ir(tpy)(bmbib)Cl][PF6]: intramolecular π⋯π interactions leading to facile synthesis and enhanced luminescence

    Z. Qu, T. Gao, J. Wen, K. Rui, H. Ma and D. Cao, Dalton Trans., 2018, 47, 9779
    DOI: 10.1039/C8DT01922C

Search articles by author

Spotlight

Advertisements