MAGNETIC SUSCEPTIBILITY STUDIES AND POSSIBLE GROUND STATE CRYSTAL FIELD SPLITTING OF 2 ORGANOMETALLIC NEPTUNIUM(4) COMPLEXES

Extensive paramagnetic susceptibility studies between liquid helium and room temperature have been carried out on polycrystalline samples of the two organometallic Np(IV)-complexes Np(C5H5)4 and (CsH5)3NpCl. From a combined interpretation of the corresponding [formula omitted]-and [formula omitted]-curves, respectively, is suggested that, in accordance with the tetrahedral molecular symmetry to be assumed for Xp(C5Hs)4. a cubic Γ8 crystal field level should lie lowest in this compound. The zero field splitting is apparently smaller than 5 cm-1. © 1969, Walter de Gruyter. All rights reserved.