Exchange coupling and magnetic blocking in bipyrimidyl radical-bridged dilanthanide complexes. Academic Article uri icon

abstract

  • The synthesis and magnetic properties of three new bipyrimidyl radical-bridged dilanthanide complexes, [(Cp*(2)Ln)(2)(μ-bpym(•))](+) (Ln = Gd, Tb, Dy), are reported. Strong Ln(III)-bpym(•-) exchange coupling is observed for all species, as indicated by the increases in χ(M)T at low temperatures. For the Gd(III)-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.

author list (cited authors)

  • Demir, S., Zadrozny, J. M., Nippe, M., & Long, J. R

complete list of authors

  • Demir, Selvan||Zadrozny, Joseph M||Nippe, Michael||Long, Jeffrey R

publication date

  • January 1, 2012 11:11 AM