title: Encapsulation and Enhanced Luminescence Properties of IrIIIComplexes within a Hexameric Self-Assembled Capsule.
abstract: Encapsulation and luminescence studies of [Ir(ppy)2(bpy)]Cl (ppy=2-phenylpyridinate, bpy=2,2'-bipyridine) within a hexameric resorcinarene capsule are reported. One IrIIIcomplex cation was encapsulated within the capsule, as demonstrated by NMR and dynamic light scattering (DLS) studies. The emission color of the IrIIIcomplex was drastically changed from orange to yellow by encapsulation, in contrast with the lack of significant changes in the absorption spectrum. The hexameric capsule effectively hampers the non-radiative pathway to increase both the luminescence quantum yield and the exited state lifetime. The luminescent properties of the encapsulated IrIIIcomplex depend on the ratio of IrIIIcomplex to the resorcinarene monomer as well as the concentration of resorcinarene monomer owing to the reversible process of self-assembly of the hexameric capsule. Quenching experiments revealed that the IrIIIcomplex in the capsule was effectively separated from quenchers.
authors.affiliation: Division of Chemistry and Materials Science, Graduate School of Engineering, Nagasaki University, Bunkyo-machi, Nagasaki, 852-8521, Japan.
authors.forename: Shinnosuke
authors.initials: S
authors.lastname: Horiuchi
authors.affiliation: Division of Chemistry and Materials Science, Graduate School of Engineering, Nagasaki University, Bunkyo-machi, Nagasaki, 852-8521, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Tanaka
authors.affiliation: Division of Chemistry and Materials Science, Graduate School of Engineering, Nagasaki University, Bunkyo-machi, Nagasaki, 852-8521, Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Sakuda
authors.affiliation: Division of Chemistry and Materials Science, Graduate School of Engineering, Nagasaki University, Bunkyo-machi, Nagasaki, 852-8521, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Arikawa
authors.affiliation: Division of Chemistry and Materials Science, Graduate School of Engineering, Nagasaki University, Bunkyo-machi, Nagasaki, 852-8521, Japan.
authors.forename: Keisuke
authors.identifier: http://orcid.org/0000-0002-2027-6333
authors.initials: K
authors.lastname: Umakoshi
keywords: Ir complexes; host-guest systems; luminescence; self-assembled capsules