Synthesis and Utility of Neptunium(III) Hydrocarbyl Complex

To extend organoactinide chemistry beyond uranium, we report the first structurally characterized transuranic hydrocarbyl complex, Np[η4-Me2NC(H)C6H5]3, 1, from reaction of NpCl4(DME)2 with four equivalents of K[Me2NC(H)C6H5]. Unlike the U(III) species, the neptunium analogue can be used to access other Np(III) complexes. The reaction of 1 with three equivalents of HE2C(2,6-Mes2-C6H3), E = O, S, yields [(2,6-Mes2-C6H3)CE2]3Np(THF)2, maintaining the trivalent oxidation state.