Structural variations in cyclopentadienyl uranium(III) iodide complexes

Eight cyclopentadienyl U(III) iodide complexes have been synthesized from UI3 and crystallographically characterized to show the variations that can occur with this ligand set and uranium in the +3 oxidation state: (C5Me5)(2)UI(THF), {[K(OEt2)(2)][(C5Me5)(2)U(mu-I)(2)]}(2), [K(18-crown-6)][(C5Me5)(2)U(mu-I)(2)], [K(2.2.2-cryptand)][(C5Me5)(2)UI2], [Li(THF)(4)][(C5Me5)(2)UI2], [Li(THF)(3)][(C5Me5)(2)UI(mu-I)], {[K(18-crown-6)](2)(mu-toluene)}{[C5H3(SiMe3)(2)](2)UI(mu-I)}(2) and [(C5Me5)U](3)(mu (3)-I)(2) (mu-I)(3)I(THF)(2). The structures show that small modifications in synthetic and crystallization procedures lead to changes in the coordination mode of the isolated product such that many structural options are available that can only be defined by X-ray crystallography. These variations highlight the many low energy options available in the reaction chemistry of this combination of metal and ligands.