Title: Cationic Iridium Complexes with Intramolecular pi-pi Interaction and Enhanced Steric Hindrance for Solid-State Light-Emitting Electrochemical Cells
Authors: Chen, Hsiao-Fan
Hung, Wen-Yi
Chen, Shou-Wei
Wang, Ting-Chih
Lin, Shih-Wei
Chou, Shu-Hua
Liao, Chih-Teng
Su, Hai-Ching
Pan, Hsiao-An
Chou, Pi-Tai
Liu, Yi-Hung
Wong, Ken-Tsung
Institute of Lighting and Energy Photonics
Issue Date: 19-Nov-2012
Abstract: Cationic iridium complexes incorporated 4,5-diaza-9,9'-spirobifluorene as N<^>N ancillary ligands, in which one (2) or two (3) phenyl groups were introduced onto 4,5-diazafluorene to afford intraligand pi-pi interactions. The X-ray crystal structures of complexes 2 and 3 show that the pendant phenyl ring forms strong intramolecular face-to-face pi-stacking with the difluorophenyl ring of the cyclometalated ligand with distances of 3.38 angstrom for complex 2 and 3.40 and 3.46 angstrom for complex 3. This pi-pi stacking interaction minimizes the expansion of the metal ligand bonds in the excited state, resulting in a longer device lifetime in the light-emitting electrochemical cell (LEC) devices.
URI: http://dx.doi.org/10.1021/ic300673k
ISSN: 0020-1669
DOI: 10.1021/ic300673k
Volume: 51
Issue: 22
Begin Page: 12114
End Page: 12121
Appears in Collections:Articles

Files in This Item:

  1. 000311173700008.pdf