title: Enhanced electric dipole transition in lanthanide complex with organometallic ruthenocene units.
abstract: Enhanced luminescence of a lanthanide complex with dynamic polarization of the excited state and molecular motion is introduced. The luminescent lanthanide complex is composed of one Eu(hfa)3 (hfa, hexafluoroacetylacetonate) and two phosphine oxide ligands with ruthenocenyl units Rc, [Eu(hfa)3(RcPO)2] (RcPO = diphenylphosphorylruthenocene). The ruthenocenyl units in the phosphine oxide ligands play an important role of switching for dynamic molecular polarization and motion in liquid media. The oxidation states of the ruthenocenyl unit (Rc(1+)/Rc(1+)) are controlled by potentiostatic polarization. Eu(III) complexes attached with bidentate phosphine oxide ligands containing ruthenocenyl units, [Eu(hfa)3(RcBPO)] (RcBPO = 1,1'-bis(diphenylphosphoryl)ruthenocene), and with bidentate phosphine oxide ligands, [Eu(hfa)3(BIPHEPO)] (BIPHEPO =1,1'-biphenyl-2,2'-diylbis(diphenylphosphine oxide), were also prepared as references. The coordination structures and electrochemical properties were analyzed using single crystal X-ray analysis, cyclic voltammetry, and absorption spectroscopy measurements. The luminescence properties were estimated using an optoelectrochemical cell. Under potentiostatic polarization, a significant enhancement of luminescence was successfully observed for [Eu(hfa)3(RcPO)2], while no spectral change was observed for [Eu(hfa)3(RcBPO)]. In this study, the remarkable enhanced luminescence phenomena of Eu(III) complex based on the dynamic molecular motion under potentiostatic polarization have been performed.
authors: †Faculty of Engineering and §Faculty of Science, Hokkaido University, N13 W8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan.
authors: Yasuchika
authors: Y
authors: Hasegawa
authors: †Faculty of Engineering and §Faculty of Science, Hokkaido University, N13 W8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan.
authors: Nao
authors: N
authors: Sato
authors: †Faculty of Engineering and §Faculty of Science, Hokkaido University, N13 W8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan.
authors: Yuichi
authors: Y
authors: Hirai
authors: †Faculty of Engineering and §Faculty of Science, Hokkaido University, N13 W8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan.
authors: Takayuki
authors: T
authors: Nakanishi
authors: †Faculty of Engineering and §Faculty of Science, Hokkaido University, N13 W8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan.
authors: Yuichi
authors: Y
authors: Kitagawa
authors: †Faculty of Engineering and §Faculty of Science, Hokkaido University, N13 W8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan.
authors: Atsushi
authors: A
authors: Kobayashi
authors: †Faculty of Engineering and §Faculty of Science, Hokkaido University, N13 W8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan.
authors: Masako
authors: M
authors: Kato
authors: †Faculty of Engineering and §Faculty of Science, Hokkaido University, N13 W8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan.
authors: Tomohiro
authors: T
authors: Seki
authors: †Faculty of Engineering and §Faculty of Science, Hokkaido University, N13 W8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan.
authors: Hajime
authors: H
authors: Ito
authors: †Faculty of Engineering and §Faculty of Science, Hokkaido University, N13 W8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan.
authors: Koji
authors: K
authors: Fushimi