Abstract
The intermolecular interaction and aggregation of the neutral complex fac-tris(2-phenylpyridinato-C2,N)iridium(III) (fac-Ir(ppy) 3) in solution was investigated. Intermolecular interactions were found to effectively decrease the luminescence lifetime via self-quenching with increasing fac-Ir(ppy)3 concentrations. A Stern-Volmer plot for quenching in acetonitrile was linear, due to bimolecular self-quenching, but curved in toluene as the result of excimer formation. 1H NMR spectra demonstrated a monomer-aggregate equilibrium which resulted in spectral shifts depending on solvent polarity. X-ray crystallography provided structural information concerning the aggregate, which is based on a tetramer consisting of two Δ-fac-Ir(ppy)3-Λ-fac-Ir(ppy)3 pairs. Offset π-π stacking of ppy ligands and electrostatic dipole-dipole interactions between complex molecules play an important role in the formation of these molecular pairs.
Original language | English |
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Pages (from-to) | 9449-9456 |
Number of pages | 8 |
Journal | Journal of Physical Chemistry B |
Volume | 117 |
Issue number | 32 |
DOIs | |
Publication status | Published - Aug 15 2013 |
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry