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Ancillary Ligand Effects on Red‐Emitting Cyclometalated Iridium Complexes
Author(s) -
Lai PoNi,
Teets Thomas S.
Publication year - 2019
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201900829
Subject(s) - iridium , ligand (biochemistry) , excited state , chemistry , chelation , photochemistry , ring (chemistry) , crystallography , inorganic chemistry , organic chemistry , atomic physics , physics , biochemistry , receptor , catalysis
In this work, a series of ten new red‐emitting heteroleptic iridium(III) complexes of the type Ir(C^N) 2 (L^X) (C^N=cyclometalating ligand, L^X=monoanionic chelating ancillary ligand) is introduced. The suite of new complexes includes two different cyclometalating ligands and five different ancillary ligands, with the primary goal of investigating the effect of the ancillary ligand structure on the excited‐state dynamics. The structural variety of the ancillary ligands permitted investigations of the effects of donor atom identity, chelate ring size, and substituents on the electronic structure and excited state properties. Electrochemical analysis showed that the ancillary ligand has a substantial effect on the energy of the HOMO, whereas the LUMO is left unperturbed. Photoluminescence spectra showed that the ancillary ligand can sometimes strongly influence the emission wavelength, but in all cases is an important determinant of the excited‐state dynamics.