Aluminum triiodide induced complexation and structural rearrangement of the hexaphospha-pentaprismane cage, P6C4tBu4

Treatment of P6C4tBu4 with the Lewis acid AlI3 in toluene at room temperature unexpectedly results in a structural rearrangement affording the ionic complex [P6C4tBu4H][AlI4] which was fully characterized by multinuclear NMR spectroscopy and a single crystal X-ray diffraction study. Supportive evidence that the reaction might involve a simple intermediate Lewis acid-base adduct [AlI3(η1-P6C4tBu4)] came from the isolation on one occasion of small number of crystals of the bis-Al adduct [{AlI3}μ-{P6C4tBu4}{AlI3}], whose molecular structure was also confirmed by a single crystal X-ray diffraction study.