title: Anion effects on the structures and magnetic properties of binuclear lanthanide single-molecule magnets.
abstract: Here we report the anion-induced changes of structures and magnetic properties in binuclear lanthanide compounds. Firstly, two Dy(3+)-based compounds, [Dy2(Mq)4(NO3)6] (1) and [Dy2(Mq)4Cl6](EtOH)2 (2) (Mq = 8-hydroxy-2-methylquinoline), were synthesized and characterized. They contain similar binuclear Dy2O2 cores, while the different peripheral anions lead to quite different coordination environments of the Dy(3+) ion. In compound 1, the Dy(3+) ion is nine-coordinated and characterized by a distorted 4,4,4-tricapped trigonal prism environment. In compound 2, the Dy(3+) ion has a highly distorted six-coordinated octahedral environment. Their Gd(3+) analogues, [Gd2(Mq)4(NO3)6] (3) and [Gd2(Mq)4Cl6](EtOH)2 (4), were also studied to investigate the magnetic interaction between metal ions. Variable-temperature dc magnetic susceptibility measurements show that all the compounds are weakly antiferromagnetically coupled. Ac magnetic susceptibility measurements reveal that both compounds 1 and 2 exhibit single-molecule magnet (SMM) behaviour, while the thermal energy barrier of 2 is significantly higher than that of 1 (Δ/k(B) = 40.0 K for 1 and Δ/k(B) = 102.4 K for 2).
authors.affiliation: State Key Laboratory of Inorganic Synthesis & Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China. zshi@mail.jlu.edu.cn.
authors.forename: Fen
authors.initials: F
authors.lastname: Yang
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhou
authors.forename: Guang
authors.initials: G
authors.lastname: Zeng
authors.forename: Guanghua
authors.initials: G
authors.lastname: Li
authors.forename: Lu
authors.initials: L
authors.lastname: Gao
authors.forename: Zhan
authors.initials: Z
authors.lastname: Shi
authors.forename: Shouhua
authors.initials: S
authors.lastname: Feng