2.2.2-Cryptand complexes of neptunium(III) and plutonium(III).

New coordination environments are reported for Np(III) and Pu(III) based on pilot studies of U(III) in 2.2.2-cryptand (crypt). The U(III)-in-crypt complex, [U(crypt)I][I], obtained from the reaction between UI and crypt, is treated with MeSiOTf (OTf = OSCF) in benzene to form the [U(crypt)(OTf)][OTf] complex. Similarly, the isomorphous Np(III) and Pu(III) complexes were obtained similarly starting from [AnI(THF)]. All three complexes (1-An; An = U, Np, Pu) contain an encapsulated actinide in a THF-soluble complex. Absorption spectroscopy and DFT calculations are consistent with 5f U(III), 5f Np(III), and 5f Pu(III) electron configurations.