Spectra of centrosymmetric rare-earth complexes: Nd³⁺-hexakis-antipyrine tri-iodide single crystals

Abstract

Polarized absorption spectra of centrosymmetric neodymium hexakis-antipyrine tri-iodide single crystals at 77 and 20° K have been discussed. The spectrum is complicated by the appearance of a large number of vibronic lines. A phase transition destroying the inversion symmetry occurs between 77 and 20°K and this was used as a tool to locate the 0-0 lines. Some of the 0-0 lines have been shown to be magnetic dipole allowed. The calculated crystal-field parameters (Stevens) are B₂⁰=200 cm_-1; B₄⁰=-130 cm^-1; B₆⁰=60 cm^-1; B₄³=3250 cm^-1; B₆³=1000 cm^-1; B₆⁶=400 cm^-1.