Reactivity of [(Ph2Si)2O3]4[Al(OH)]4 and [(Ph2Si)2O3]4[Al(OLi)]4 towards NaOEt and LiOH. Synthesis of new twelve-membered alumopolysiloxane rings

The reaction between [(Ph2Si)2O3]4[Al(OH)]4 (1) or [(Ph2Si)2O3]4[Al(OLi)]4 (2) with sodium ethoxide, or lithium hydroxide in presence of CuI·H2O leads to the formation of new alumopolysiloxane compounds. Indeed, transformations of 1 under the partial incorporation of the reactants are found giving rise to new heteroleptic inorganic macrocycles. The molecular structure of [(Ph2Si)2O3]4[Al(ONa)]2[Al(OH)(NaOEt)]2·2Et2O (3) and [(Ph2Si)2O3]4[Al(OLi)]2[Al(OH)(LiOH)]2·2Et2O·2THF (4) have been determined by single-X-ray diffraction analysis. Both alumosiloxanes 3 and 4 are constituted by a twelve-membered ring.