title: Tetraanionic biphenyl lanthanide complexes as single-molecule magnets.
abstract: Inverse sandwich biphenyl complexes [(NN(TBS))Ln]2(μ-biphenyl)[K(solvent)]2 [NN(TBS) = 1,1'-fc(NSi(t)BuMe2)2; Ln = Gd, Dy, Er; solvent = Et2O, toluene; 18-crown-6], containing a quadruply reduced biphenyl ligand, were synthesized and their magnetic properties measured. One of the dysprosium biphenyl complexes was found to exhibit antiferromagnetic coupling and single-molecule-magnet behavior with Ueff of 34 K under zero applied field. The solvent coordinated to potassium affected drastically the nature of the magnetic interaction, with the other dysprosium complex showing ferromagnetic coupling. Ab initio calculations were performed to understand the nature of magnetic coupling between the two lanthanide ions bridged by the anionic arene ligand and the origin of single-molecule-magnet behavior.
authors.affiliation: Department of Chemistry and Biochemistry, University of California , Los Angeles, California 90095, United States.
authors.forename: Wenliang
authors.initials: W
authors.lastname: Huang
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Le Roy
authors.forename: Saeed I
authors.initials: SI
authors.lastname: Khan
authors.forename: Liviu
authors.initials: L
authors.lastname: Ungur
authors.forename: Muralee
authors.initials: M
authors.lastname: Murugesu
authors.forename: Paula L
authors.initials: PL
authors.lastname: Diaconescu