A Trinuclear Radical-Bridged Lanthanide Single-Molecule Magnet.
Assembly of the triangular, organic radical-bridged complexes Cp*6Ln3(μ3-HAN) (Cp*=pentamethylcyclopentadienyl; Ln=Gd, Tb, Dy; HAN=hexaazatrinaphthylene) proceeds through the reaction of Cp*2Ln(BPh4) with HAN under strongly reducing conditions. Significantly, magnetic susceptibility measurements of these complexes support effective magnetic coupling of all three LnIIIcenters through the HAN3-.radical ligand. Thorough investigation of the DyIIIcongener through both ac susceptibility and dc magnetic relaxation measurements reveals slow relaxation of the magnetization, with an effective thermal relaxation barrier of Ueff=51 cm-1. Magnetic coupling in the DyIIIcomplex 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.
Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA.
Colin A
CA
Gould
Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA.
Lucy E
LE
Darago
Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA.
Miguel I
MI
Gonzalez
Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstrasse 4, 37077, Göttingen, Germany.
Selvan
S
Demir
Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA.|Department of Chemical and Biomolecular Engineering, University of California, Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
Jeffrey R
JR
Long
cyclopentadienyl ligands; lanthanides; molecular magnetism; non-innocent ligands; radicals