A Spectroscopic Investigation of the Electronic Structure of Neptunyl Ions

Emission spectra of NpO2Cl42− doped in a Cs2ZrCl6 matrix have been measured between 6000 and 7200 cm-1. An f-f transition has been assigned, and vibronic structure on this origin is reported. These electronic and vibrational energies are compared with previous studies including the theoretical work of Pitzer and co-workers, and the spectroscopic work of Denning and co-workers.