Synthesis of Trimethyltriazacyclohexane (Me₃tach) Sandwich Complexes of Uranium, Neptunium, and Plutonium Triiodides: (Me₃tach)₂AnI₃

1,3,5-Trimethyl-1,3,5-triazacyclohexane (Me3tach) readily complexes uranium triiodide to form (Me3tach)2UI3. The complex is soluble in THF and arenes and can function as a source of UI3 to form organometallic U(III) complexes. When dissolved in pyridine (py), (Me3tach)2UI3 forms (Me3tach)UI3(py)2. A related complex with the larger 1,4,7-trimethyl-1,4,7-triazacyclononane (Me3tacn) ligand, namely (Me3tacn)UI3(THF), was synthesized for comparison. Since X-ray quality crystals of (Me3tach)2UI3 can be synthesized in high yield even with small-scale reactions, the system is ideal for extension to transuranium elements. Accordingly, the neptunium and plutonium complexes (Me3tach)2NpI3 and (Me3tach)2PuI3 were synthesized in an analogous manner from NpI3(THF)4 and PuI3(THF)4, respectively.