title: Novel stoichiometrically erbium-ytterbium cocrystalline complex exhibiting enhanced near-infrared luminescence.
abstract: Three beta-diketonate complexes of erbium and ytterbium, Er(HFA)3(TPPO)3, Yb(HFA)3(TPPO)3, and Er(1/2)Yb(1/)(2)(HFA)3(TPPO)2 (HFA = hexafluoroacetylacetonate, TPPO = triphenylphosphine oxide) are synthesized and structurally characterized, and their luminescent properties are examined in detail. Compared with monometallic complexes Er(HFA)3(TPPO)3 and Er(HFA)3(TPPO)3, the stoichiometrically Er-Yb cocrystalline complex Er(1/2)Yb(1/2)(HFA)3(TPPO)2 exhibits special indirect near-infrared (NIR) luminescence with the acceptor and sensitizer (donor) coexisting in a single crystal. Of interest is that the NIR luminescence of the erbium ion in Er(1/2)Yb(1/2)(HFA)3(TPPO)2 is significantly enhanced because of the coexistence of the ytterbium ion through the energy-transfer between the ytterbium and erbium ions. The estimated donor-acceptor energy-transfer critical radii R(C,DA), obtained from the Förster model, are in good agreement with those determined from the single X-ray crystal structure, confirming the dipole-dipole character for such a Yb-Er energy-transfer process.
authors.affiliation: Department of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhong
authors.forename: Huaishan
authors.initials: H
authors.lastname: Wang
authors.forename: Guodong
authors.initials: G
authors.lastname: Qian
authors.forename: Zhiyu
authors.initials: Z
authors.lastname: Wang
authors.forename: Jiahua
authors.initials: J
authors.lastname: Zhang
authors.forename: Jianrong
authors.initials: J
authors.lastname: Qiu
authors.forename: Minquan
authors.initials: M
authors.lastname: Wang