The reaction of the oligoalumosiloxane [Ph2SiO]8[AlO(OH)]4(1) with hexamethyldisilazane leads to the triple ionic [Ph2SiO]8[AlO2]2[AlO(O-SiMe3)]2[NH4-THF]2∙2 THF (2) and in the presence of pyridine to [Ph2SiO]8[AlO1.5]4∙2py∙1.5 C7H8(3). Apart from the usual characterization techniques (NMR and IR spectroscopy) the molecular structures of2and3have been determined by single-X-ray diffraction analyses. Both alumosiloxanes2and3present new types of molecular structures with a central four membered Al2O2-ring, on which the further aluminium atoms are attached via oxygen atoms. This leads to an Al4-lozenge, which is centered in subtriangles by oxygen atoms.