Single-crystal magnetic properties of lanthanide complexes. Part IV. Tri-iodohexakis(antipyrine)neodymium(III)

Abstract

The principal magnetic moments of crystals of tri-iodohexakis(antipyrine)neodymium(III)(antipyrine is 2,3-dimethyl-1-phenyl-Δ³-pyrazolin-5-one) have been measured in the temperature range 300–90 K. These are interpreted within a free-ion f^3,4l term as basis, perturbed by a crystal field of D_3d symmetry. The point-charge potential leads to second-, fourth-, and sixth-order radial parameters ρ₂, ρ₄, and ρ₆, and θ, the effective angle subtended by any metal–oxygen bond and the three-fold symmetry axis. Mean moments fix ρ₄ and ρ₆ as 700 ± 200 cm^–1 and 425 ± 50 cm^–1, respectively. Magnetic anisotropies set ranges for A₂⁰〈r²〉, related to the coefficient of the second-order potential, as 140–220 cm^–1 at 300 K and 200–350 cm^–1 at 100 K. These ranges depend on ρ₂, a property not shared by the magnetic properties of the cerium, terbium, or ytterbium analogues.