UI4(1,4-dioxane)2, [UCl4(1,4-dioxane)]2, and UI3(1,4-dioxane)1.5: Stable and Versatile Starting Materials for Low- and High-Valent Uranium Chemistry

The uranium(III) and uranium(IV) iodide complexes UI3(1,4-dioxane)1.5 and UI4(1,4-dioxane)2 have been easily prepared in high yield by reacting uranium turnings with a 1,4-dioxane solution of iodine under mild conditions. The two complexes exhibit outstanding thermal stability and are excellent precursors to a variety of uranium(III), uranium(IV), and uranium(VI) alkoxide, amide, organometallic, and halide compounds, including a safe, room-temperature synthesis of [UCl4(1,4-dioxane)]2, which is a useful synthetic alternative to UCl4.