An aluminium-oxide-isopropoxide cluster with peripheral ammonia ligands

The reaction of toluene solutions of aluminium isopropoxide with ammonia gas, without exclusion of moisture, affords high yields of a decanuclear aluminium-oxide-isopropoxide-ammonia cluster of the composition [Al₁₀O₆(OiPr)₁₈(NH₃)₈]. The compact centrosymmetric cluster units feature tetra-, penta-and hexa-coordinate aluminium atoms, tri-and tetra-coordinate interstitial oxygen atoms, and bridging and terminal isopropoxide groups. The ammonia molecules occupy peripheral positions at two types of aluminium atoms.