title: Tuning the Origin of Magnetic Relaxation by Substituting the 3d or Rare-Earth Ions into Three Isostructural Cyano-Bridged 3d-4f Heterodinuclear Compounds.
abstract: Three isostructural cyano-bridged 3d-4f compounds, [YFe(CN)6(hep)2(H2O)4] (1), [DyFe(CN)6(hep)2(H2O)4] (2), and [DyCo(CN)6(hep)2(H2O)4] (3), were successfully assembled by site-targeted substitution of the 3d or rare-earth ions. All compounds have been structurally characterized to display slightly distorted pentagonal-bipyramidal local coordination geometry around the rare-earth ions. Magnetic analyses revealed negligible magnetic coupling in compound 1, antiferromagnetic intradimer interaction in 2, and weak ferromagnetic coupling through dipolar-dipolar interaction in 3. Under an applied direct-current (dc) field, 1 (Hdc = 2.5 kOe, τ0 = 1.3 × 10(-7) s, and Ueff/kB = 23 K) and 3 (Hdc = 2.0 kOe, τ0 = 7.1 × 10(-11) s, and Ueff/kB = 63 K) respectively indicated magnetic relaxation behavior based on a single [Fe(III)]LS ion and a Dy(III) ion; nevertheless, 2 (Hdc = 2.0 kOe, τ0 = 9.7 × 10(-8) s, and Ueff/kB = 23 K) appeared to be a single-molecule magnet based on a cyano-bridged DyFe dimer. Compound 1, which can be regarded as a single-ion magnet of the [Fe(III)]LS ion linked to a diamagnetic Y(III) ion in a cyano-bridged heterodimer, represents one of the rarely investigated examples based on a single Fe(III) ion explored in magnetic relaxation behavior. It demonstrated that the introduction of intradimer magnetic interaction of 2 through a cyano bridge between Dy(III) and [Fe(III)]LS ions negatively affects the energy barrier and χ″(T) peak temperature compared to 3.
authors.affiliation: Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Hubei University , Wuhan 430062, P. R. China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Hubei University , Wuhan 430062, P. R. China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Hubei University , Wuhan 430062, P. R. China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Xie
authors.affiliation: Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Hubei University , Wuhan 430062, P. R. China.
authors.forename: Hui-Li
authors.initials: HL
authors.lastname: Li
authors.affiliation: Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Hubei University , Wuhan 430062, P. R. China.
authors.forename: Wen-Hua
authors.initials: WH
authors.lastname: Zhu
authors.affiliation: Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Hubei University , Wuhan 430062, P. R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.affiliation: Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Hubei University , Wuhan 430062, P. R. China.
authors.forename: Xun-Qing
authors.initials: XQ
authors.lastname: Dong
authors.affiliation: Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Hubei University , Wuhan 430062, P. R. China.
authors.forename: Wei-Xun
authors.initials: WX
authors.lastname: He
authors.affiliation: Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Hubei University , Wuhan 430062, P. R. China.
authors.forename: Jin-Chao
authors.initials: JC
authors.lastname: Ren
authors.affiliation: College of Science, Huazhong Agricultural University , Wuhan 430070, P. R. China.
authors.forename: Ling-Zhi
authors.initials: LZ
authors.lastname: Liu
authors.affiliation: Institute of Inorganic Chemistry, Karlsruhe Institute of Technology , Engesserstrasse 15, Karlsruhe 76131, Germany.
authors.forename: Annie K
authors.initials: AK
authors.lastname: Powell