The effect of the disposition of coordinated oxygen atoms on the magnitude of the energy barrier for magnetization reversal in a family of linear trinuclear Zn-Dy-Zn complexes with a square-antiprism DyO8 coordination sphere

• Published in: Dalton transactions : an international journal of inorganic chemistry Vol. 46; no. 13; pp. 4278 - 4286
• Main Authors: Oyarzabal, Itziar, Rodríguez-Diéguez, Antonio, Barquín, Montserrat, Seco, José M, Colacio, Enrique
• Format: Journal Article
• Language: English
• Published: 07.04.2017
• Subjects: Barriers; Crystallization; Distortion; Ligands; Magnetization; Magnetization reversal; Oxygen atoms; Solvents
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c7dt00138j

A series of trimetallic Zn-Dy-Zn complexes of the general formula [ZnX(μ-L)Dy(μ-L)XZn]Y·nS, where H2L is the compartmental ligand N,N'-dimethyl-N,N'-bis(2-hydroxy-3-formyl-5-bromobenzyl)ethylenediamine, X is the coligand (X = Cl, Br, I and N3), Y is the counteranion and S are the crystallization solvent molecules have been synthesized and magnetically characterized. In all these complexes, the Dy(iii) ions exhibit DyO8 coordination environments with a slightly distorted square-antiprism D4d symmetry. Due to the disposition of the oxygen atoms around the Dy(iii) ions, large easy-axis anisotropy is expected, which is responsible for the high thermal energy barriers for the reversal of the magnetization observed at zero field (in the 144-170 K range for all complexes). A preliminary correlation between the disposition of the oxygen atoms of the ligand (phenoxo and aldehyde) in the DyO8 coordination sphere and the value of Ueff has been established.