Exchange Coupling and Magnetic Blocking in Bipyrimidyl Radical-Bridged Dilanthanide Complexes

被引：340

作者：

Demir, Selvan ^{[1
]}

Zadrozny, Joseph M. ^{[1
]}

Nippe, Michael ^{[1
]}

Long, Jeffrey R. ^{[1
]}

机构：

[1] Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 2012年 / 134卷 / 45期

基金：

美国国家科学基金会;

关键词：

SINGLE-MOLECULE-MAGNET; SPIN-LATTICE-RELAXATION; RARE-EARTH SALTS; LANTHANIDE COMPLEXES; BEHAVIOR; MONONUCLEAR; DYSPROSIUM(III); TETRANUCLEAR; DILUTION; LIGANDS;

D O I：

10.1021/ja308945d

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The synthesis and magnetic properties of three new bipyrimidyl radical bridged dilanthanide complexes, [(Cp*(2)Ln)(2)(mu-bpym(center dot))](+) (Ln = Gd, Tb, Dy), are reported. Strong Ln(III)-bpym(center dot-) exchange coupling is observed for all species, as indicated by the increases in chi T-M at low temperatures. For the (GdI)-I-II-containing complex, a fit to the data reveals antiferromagnetic coupling with J = -10 cm(-1) to give an S = 13/2 ground state. The Tb-III and Dy-III congeners show single-Molecule magnet behavior with relaxation barriers of U-eff = 44(2) and 87.8(3) cm(-1), respectively, a consequence of the large magnetic anisotropies-imparted by these ions. Significantly, the latter Complex exhibits a divergence of the field cooled and zero-field-cooled dc susceptibility data at 6.5 K and magnetic hysteresis below this temperature.

引用

页码：18546 / 18549

页数：4

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