title: Controlled synthesis of heterotrimetallic single-chain magnets from anisotropic high-spin 3 d-4 f nodes and paramagnetic spacers.
abstract: By using the node-and-spacer approach in suitable solvents, four new heterotrimetallic 1D chain-like compounds (that is, containing 3d-3d'-4f metal ions), {[Ni(L)Ln(NO(3))(2)(H(2)O)Fe(Tp*)(CN)(3)]⋅2 CH(3)CN⋅CH(3)OH}(n) (H(2)L = N,N'-bis(3-methoxysalicylidene)-1,3-diaminopropane, Tp* = hydridotris(3,5-dimethylpyrazol-1-yl)borate; Ln = Gd (1), Dy (2), Tb (3), Nd (4)), have been synthesized and structurally characterized. All of these compounds are made up of a neutral cyanide- and phenolate-bridged heterotrimetallic chain, with a {-Fe-C≡N-Ni(-O-Ln)-N≡C-}(n) repeat unit. Within these chains, each [(Tp*)Fe(CN)(3)](-) entity binds to the Ni(II) ion of the [Ni(L)Ln(NO(3))(2)(H(2)O)](+) motif through two of its three cyanide groups in a cis mode, whereas each [Ni(L)Ln(NO(3))(2)(H(2)O)](+) unit is linked to two [(Tp*)Fe(CN)(3)](-) ions through the Ni(II) ion in a trans mode. In the [Ni(L)Ln(NO(3))(2)(H(2)O)](+) unit, the Ni(II) and Ln(III) ions are bridged to one other through two phenolic oxygen atoms of the ligand (L). Compounds 1-4 are rare examples of 1D cyanide- and phenolate-bridged 3d-3d'-4f helical chain compounds. As expected, strong ferromagnetic interactions are observed between neighboring Fe(III) and Ni(II) ions through a cyanide bridge and between neighboring Ni(II) and Ln(III) (except for Nd(III) ) ions through two phenolate bridges. Further magnetic studies show that all of these compounds exhibit single-chain magnetic behavior. Compound 2 exhibits the highest effective energy barrier (58.2 K) for the reversal of magnetization in 3d/4d/5d-4f heterotrimetallic single-chain magnets.
authors.affiliation: State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
authors.forename: Min-Xia
authors.initials: MX
authors.lastname: Yao
authors.forename: Qi
authors.initials: Q
authors.lastname: Zheng
authors.forename: Kang
authors.initials: K
authors.lastname: Qian
authors.forename: You
authors.initials: Y
authors.lastname: Song
authors.forename: Song
authors.initials: S
authors.lastname: Gao
authors.forename: Jing-Lin
authors.initials: JL
authors.lastname: Zuo