Neptunium(V) Complexes With Lipophilic N-Donor Extractant Ligands

Neptunium(V) complexes with N-donor lipophilic extractants, 2,2 ':6 ',2 ''-terpyridine (Terpy), 2,4,6-tri-2-pyridyl-1,3,5-triazine (TPTZ), and 6,6'-bis(5,6-diethyl-1,2,4-triazin-3-yl)-2,2'bipyridine (C2-BTBP), have been synthesized and characterized by X-ray crystallography as well as vis-NIR and IR spectroscopy. The structures display coordination of one N-donor ligand to the NpO2+ group. In all cases, the Np atom is found in a pentagonal bipyramidal coordination environment. The structures exhibit 0D topologies, except the neptunium formate complex with terpyridine, where the anion acts as a bridging ligand and forms an infinite chain structure. The complex with C2-BTBP is the first example of a structurally characterized Np complex with this ligand. Vis-NIR and IR spectra of the compounds correlate with their crystal structures.