78762-95-5Relevant articles and documents
Decomposition of high-oxygen content organoaluminum compounds. The formation and structure of the [Al7O6Me16]- anion
Atwood, Jerry L.,Hrncir, Duane C.,Priester, Ralph D.,Rogers, Robin D.
, p. 985 - 989 (1983)
The unusual anion [Al7O6Me16]- has been encountered in the decomposition pathways of two different high-oxygen content organoaluminum compounds, K[Al2Me6O2] and presumably Cs2[Al2Me6O]. It is likely that these two compounds pass through the same intermediate and that the [Al7O6Me16]- ion is a thermodynamic sink. In both cases crystalline material has been isolated, and X-ray structural determinations have been carried out. K[Al7O6Me16]·C6H6 crystalizes in the triclinic space group P1 with lattice parameters a = 12.095 (5) A?, b = 12.222 (5) A?, c = 13.893 (5) A?, α = 105.56 (3)°, β = 94.52 (2)°, γ = 83.98 (2)°, and ρcalcd = 1.09 g cm-3 for Z = 2. Least-squares refinement gave a final R value of 0.042 for 2509 independent observed reflections. Cs[Al7O6Me16]·3C6H 5Me belongs to the cubic space group P213 with a = 17.512 (8) A? and ρcalcd = 1.16 g cm-3 for Z = 4. Refinement based on 460 observed reflections gave a final R of 0.075. The anion for the cesium salt lies on a crystallographic threefold axis. The structure consists of an open Al6O6 cage capped by the seventh Al atom which is bonded to three alternate O atoms in the cage. The six Al atoms are bonded to two terminal methyl groups each, while the unique Al is bonded to only one methyl group. Each O atom is three coordinate: the ones on the exterior (not bonded to the unique Al atom) bridge two Al atoms and are also bonded to one methyl group each.
