Analysis of the optical spectrum of Np(BD4)4 diluted in Zr(BD4)4 and the magnetic properties of Np(BH4)4 and Np(BH3CH3)4

Abstract
The optical spectrum of Np(BD4)4/Zr(BD4)4 is reported and analyzed. The parameter values obtained are consistent with those for U(BD4)4/Hf(BD4)4. A total of 46 levels were fit with σ=84 cm1. EPR data on Np(BD4)4/Zr(BD4)4 and Np(BH3CH3)4/Zr(BH3CH3)4 and the magnetic susceptibility of Np(BH3CH3)4 are reported. They could be fit with the eigenvectors from the optical analysis only by the inclusion of orbital reduction factors k=0.885 for Np(BD4)4 and 0.862 for Np(BH3CH3)4. These values indicate greater covalency for the methylborohydride.