Low-valent molecular plutonium halide complexes

Treatment of plutonium metal with 1.5 equiv of bromine in tetrahydrofuran (thf) led to isolation of PuBr3(thf)(4) (1), which is a new versatile synthon for exploration of non-aqueous Pu(III) chemistry. Adventitious water in the system resulted in structural characterization of the eight-coordinate complex [PuBr2(H2O)(6)][Br] (2). The crystal structure of Pul(3)(thf)(4) (3) has been determined for the first time and is isostructural with Ul(3)(thf)(4). Attempts to form a bis(imido) plutonyl(VI) moiety ([Pu(NR)(2)](2+)) by oxidation of Pul(3)(PY)(4) with iodine and (BuNH2)-Bu-t resulted in crystallization of the Pu(III) Complex [Pul(2)(thf)(4)(py)][I-3] (4). Dissolution of a Pu(IV) carbonate with a HCl/Et2O solution in thf gave the mixed valent (III/IV) complex salt [PuCl2(thf)(5)][PuCl5(thf)] (5) as the only tractable product. Oxidation of Pu[N(SiMe3)(2)](3) with TeCl4 afforded the Pu(IV) complex Pu[N(SiMe3)(2)](3)Cl (6), which may prove to be a useful entry route for investigation of organometallic/non-aqueous tetravalent plutonium chemistry.