Small-Scale Metal-Based Syntheses of Lanthanide Iodide, Amide, and Cyclopentadienyl Complexes as Analogues for Transuranic Reactions.

Small-scale reactions of the Pu analogues La, Ce, and Nd have been explored in order to optimize reaction conditions for milligram scale reactions of radioactive plutonium starting from the metal. Oxidation of these lanthanide metals with iodine in ether and pyridine has been studied, and LnI3 (Et2 O)x (1-Ln; x = 0.75-1.9) and LnI3 (py)4 (2-Ln; py = pyridine, NC5 H5 ) have been synthesized on scales ranging from 15 mg to 2 g. The THF adducts LnI3 (THF)4 (3-Ln) were synthesized by dissolving 1-Ln in THF. The viability of these small-scale samples as starting materials for amide and cyclopentadienyl f-element complexes was tested by reacting KN(SiMe3 )2 , KCp' (Cp' = C5 H4 SiMe3 ), KCp'' (Cp'' = C5 H3 (SiMe3 )2 -1,3), and KC5 Me4 H with 1-Ln generated in situ. These reactions produced Ln[N(SiMe3 )2 ]3 (4-Ln), Cp'3 Ln (5-Ln), Cp″3 Ln (6-Ln), and (C5 Me4 H)3 Ln (7-Ln), respectively. Small-scale samples of Cp'3 Ce (5-Ce) and Cp'3 Nd (5-Nd) were reduced with potassium graphite (KC8 ) in the presence of 2.2.2-cryptand to check the viability of generating the crystallographically characterizable Ln2+ complexes [K(2.2.2-cryptand)][Cp'3 Ln] (8-Ln; Ln = Ce, Nd).