Single-crystal magnetic properties of lanthanide complexes. Part VIII. Hexakis(antipyrine)praseodymium(III) tri-iodide

Abstract

The principal and average magnetic moments of hexakis(antipyrine)praseodymium(III) tri-iodide (antipyrine is 2,3-dimethyl-1-phenyl-Δ³-pyrazolin-5-one), have been measured in the temperature range 300—80 K. The temperature dependence of the anisotropy χ_∥–χ⊥ is unusual compared with other lanthanide ions in this series, but is directly reproduced by the same D_3d point-charge crystal-field model used previously. Calculations have used a ³H₄+³H₅ free-ion basis corrected for the effects of intermediate coupling. Selected calculations show that inclusion of the complete ³H and ³F terms in the basis is unnecessary. Values of ρ₄ and ρ₆, the fourth and sixth-order radial parameter, are estimated both to lie in the range 600 ± 100 cm^–1. A value for A₂〈r²〉 related to the second-order term in the potential, is estimated as 290 ± 50 cm^–1.