Intermolecular interactions and aggregation of fac -Tris(2- phenylpyridinato- C 2, N)iridium(III) in nonpolar solvents

Satoshi Takayasu, Takayoshi Suzuki, Kazuteru Shinozaki

Research output: Contribution to journalArticle

30 Citations (Scopus)


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 languageEnglish
Pages (from-to)9449-9456
Number of pages8
JournalJournal of Physical Chemistry B
Issue number32
Publication statusPublished - Aug 15 2013

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Materials Chemistry

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