A Trinuclear Radical-Bridged Lanthanide Single-Molecule Magnet

Colin A Gould; Lucy E Darago; Miguel I Gonzalez; Selvan Demir; Jeffrey R Long

doi:10.1002/anie.201612271

A Trinuclear Radical-Bridged Lanthanide Single-Molecule Magnet

Angew Chem Int Ed Engl. 2017 Aug 14;56(34):10103-10107. doi: 10.1002/anie.201612271. Epub 2017 Feb 3.

Authors

Colin A Gould¹, Lucy E Darago¹, Miguel I Gonzalez¹, Selvan Demir², Jeffrey R Long^{1

3}

Affiliations

¹ Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA.
² Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstrasse 4, 37077, Göttingen, Germany.
³ Department of Chemical and Biomolecular Engineering, University of California, Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.

PMID: 28157259
DOI: 10.1002/anie.201612271

Abstract

Assembly of the triangular, organic radical-bridged complexes Cp*₆ Ln₃ (μ₃ -HAN) (Cp*=pentamethylcyclopentadienyl; Ln=Gd, Tb, Dy; HAN=hexaazatrinaphthylene) proceeds through the reaction of Cp*₂ Ln(BPh₄ ) with HAN under strongly reducing conditions. Significantly, magnetic susceptibility measurements of these complexes support effective magnetic coupling of all three Ln^III centers through the HAN^3-. radical ligand. Thorough investigation of the Dy^III congener through both ac susceptibility and dc magnetic relaxation measurements reveals slow relaxation of the magnetization, with an effective thermal relaxation barrier of U_eff =51 cm^-1 . Magnetic coupling in the Dy^III complex enables a large remnant magnetization at temperatures up to 3.0 K in the magnetic hysteresis measurements and hysteresis loops that are open at zero-field up to 3.5 K.

Keywords: cyclopentadienyl ligands; lanthanides; molecular magnetism; non-innocent ligands; radicals.

Publication types

Research Support, Non-U.S. Gov't