[AnI(THF)] (An = Np, Pu) Preparation Bypassing An Metal Precursors: Access to Np/Pu Nonaqueous and Organometallic Complexes.

Direct comparison of homologous molecules provides a foundation from which to elucidate both subtle and patent changes in reactivity patterns, redox processes, and bonding properties across a series of elements. While trivalent molecular U chemistry is richly developed, analogous Np or Pu research has long been hindered by synthetic routes often requiring scarcely available metallic-phase source material, high-temperature solid-state reactions producing poorly soluble binary halides, or the use of pyrophoric reagents. The development of routes to nonaqueous Np/Pu from widely available precursors can potentially transform the scope and pace of research into actinide periodicity. Here, aqueous stocks of An (An = Np, Pu) are dehydrated to well-defined [AnCl(DME)] (DME = 1,2-dimethoxyethane), and then a single-step halide exchange/reduction employing MeSiI produces [AnI(THF)] (THF = tetrahydrofuran) in a high to nearly quantitative crystalline yield (with I and MeSiCl as easily removed byproducts). We demonstrate the synthetic utility of these An-iodide molecules, prepared by metal-free routes, through characterization of archetypal complexes including the -silylamide, [Np{N(SiMe)}], and bent metallocenes, [An(CMe)(I)(THF)] (An = Np, Pu)─chosen because both motifs are ubiquitous in Th, U, and lanthanide research. The synthesis of [Np{N(Se═PPh)}] is also reported, completing an isomorphous series that now extends from U to Am and is the first characterized Np-Se bond.