title: Ligand field effect tuned magnetic behaviors of two chain compounds based on Mn(III)3O units: from slow magnetic relaxation to metamagnetism.
abstract: Two chain compounds built with anti-anti acetate bridged Mn(III)(3)O units, [Mn(3)O(Clppz)(3)(EtOH)(4)(OAc)](n) (1) and [Mn(3)O(Clppz)(3)(EtOH)(2)(OAc)](n) (2), were synthesized and characterized. The magnetic studies indicate that 1 is a single-chain magnet with two slow magnetization relaxation processes which has for the first time been found in this type of chain complex, while 2 shows a field-induced metamagnetic behavior. The quite different magnetic behaviors resulted from the different number of coordinated ethanol molecules on the Mn(III)(3)O unit, four ethanol molecules for 1, and two ethanol molecules for 2. The best fittings to the experimental magnetic susceptibilities gave J(1) = -2.72 cm(-1), J(2) = -4.34 cm(-1), zJ = 1.24 cm(-1) for 1 and J(1) = -5.91 cm(-1), J(2) = -0.98 cm(-1), zJ = 1.71 for 2 above 30 K. The positive zJ values indicate the presence of weak ferromagnetic interactions between the trinuclear units via acetate bridges in 1 and 2.
authors.affiliation: Department of Chemistry, College of Science, Shanghai University, Shanghai 200444, P.R. China. yuelingbai@shu.edu.cn
authors.forename: Yue-Ling
authors.initials: YL
authors.lastname: Bai
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Bao
authors.forename: Shourong
authors.initials: S
authors.lastname: Zhu
authors.forename: Jianhui
authors.initials: J
authors.lastname: Fang
authors.forename: Jun
authors.initials: J
authors.lastname: Tao