Multimetallic and Mixed Environment Iridium(III) Complexes: A Modular Approach to Luminescence Tuning Using a Host Platform

5 years ago

Multimetallic and Mixed Environment Iridium(III) Complexes: A Modular Approach to Luminescence Tuning Using a Host Platform

Victoria E. Pritchard, Eli Zysman-Colman, Michaele J. Hardie, Diego Rota Martir

Mononuclear and trinuclear bis-cyclometallated IrIII complexes of the host ligands tris(4-[4′-methyl-2,2′-bipyridyl]methyl)cyclotriguaiacylene (L1) and tris(4-(4′-methyl-2,2′- bipyridyl)carboxy)cyclotriguaiacylene (L2) have been prepared. Complexes [{Ir(ppy)2}3(L1)](PF6)3 (1.1), [{Ir(ppy)2}(L1)](PF6)3 (1.2), [{Ir(ppy)2}3(L2)](PF6)3 (2.1) and [{Ir(ppy)2}(L2)](PF6)3 (2.2) (where ppy=phenylpyridinato) showed distinct photophysical properties depending on the L ligand. Complexes featuring the L1 ligand were comparatively blue-shifted in solution, with longer lifetimes and higher quantum yields. The mixed bis-cyclometallated IrIII complexes [{Ir(ppy)2}{Ir(dFppy)2}2(L1)](PF6)3 (1.3), [{Ir(ppy)2}{Ir(dFppy)2}2(L2)](PF6)3 (2.3), [{Ir(ppy)2}2{Ir(dFppy)2}(L1)](PF6)3 (1.4) and [{Ir(ppy)2}2{Ir(dFppy)2}(L2)](PF6)3 (2.4) (where dFppy=2,4-difluorophenylpyrinato) were also synthesised. Steady-state and time-resolved spectroscopy, along with electrochemical investigations, show that the Ir(III) chromophores within these mixed Ir-environment species behave as isolated centres, with no energy transfer or electronic communication between them. Multinuclear lighting: Luminescent mono- and trinuclear bis-cyclometallated IrIII complexes featuring cyclotriguaiacylene-type ligands are reported, including mixed-Ir environment complexes with no energy transfer or electronic communication.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/chem.201700237