title: Luminescent Europium(III) Coordination Zippers Linked with Thiophene-Based Bridges.
abstract: Novel Eu(III) coordination polymers [Eu(hfa)3 (dpt)]n (dpt: 2,5-bis(diphenylphosphoryl)thiophene) and [Eu(hfa)3 (dpedot)]n (dpedot: 2,5-bis(diphenylphosphoryl)ethylenedioxythiophene) with hydrogen-bonded zipper structures are reported. The coordination polymers are composed of Eu(III) ions, hexafluoroacetylacetonato ligands, and thiophene-based phosphine oxide bridges. The zig-zag orientation of single polymer chains induced the formation of densely packed coordination structures with multiple intermolecular interactions, resulting in thermal stability above 300 °C. They exhibit a high intrinsic emission quantum yield (ca. 80 %) due to their asymmetrical and low-vibrational coordination structures around Eu(III) ions. Furthermore, the characteristic alternative orientation of substituents also contributes to the dramatically high ligand-to-metal energy transfer efficiencies of up to 80 % in the solid state.
authors.affiliation: Graduate School of Chemical Sciences and Engineering, Hokkaido University, Kita-13 Jo, Nishi-8 Chome, Sapporo, Hokkaido, 060-8628, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Hirai
authors.affiliation: Faculty of Engineering, Hokkaido University, Kita-13 Jo, Nishi-8 Chome, Sapporo, Hokkaido, 060-8628, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakanishi
authors.affiliation: Faculty of Engineering, Hokkaido University, Kita-13 Jo, Nishi-8 Chome, Sapporo, Hokkaido, 060-8628, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kitagawa
authors.affiliation: Faculty of Engineering, Hokkaido University, Kita-13 Jo, Nishi-8 Chome, Sapporo, Hokkaido, 060-8628, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Fushimi
authors.affiliation: Faculty of Engineering, Hokkaido University, Kita-13 Jo, Nishi-8 Chome, Sapporo, Hokkaido, 060-8628, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Seki
authors.affiliation: Faculty of Engineering, Hokkaido University, Kita-13 Jo, Nishi-8 Chome, Sapporo, Hokkaido, 060-8628, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Ito
authors.affiliation: Faculty of Engineering, Hokkaido University, Kita-13 Jo, Nishi-8 Chome, Sapporo, Hokkaido, 060-8628, Japan. hasegaway@eng.hokudai.ac.jp.
authors.forename: Yasuchika
authors.initials: Y
authors.lastname: Hasegawa
keywords: coordination polymers; energy transfer; europium; luminescence; thermal stability