Transformations of the polycyclic Alumosiloxane Al2(OSiPh2OSiPh2O)3 into new Polycycles and Co(II) and In(III) derivatives of (Ph2SiO)8[Al(O)OH]4

Abstract

In the presence of water and amines the etherate of bicyclic Al2(OSiPh2OSiPh2O)3 (II a) can be used to generate novel alumosiloxane polycycles like [O(Ph2SiOSiPh2)O−]2Al2O[O(Ph2SiOSiPh2)O] ⋅ 2 H2N+Et2 (1), [O(Ph2SiOSiPh2)O−]2Al2[O(Ph2Si)O]2 ⋅ 2 HN+Et3 (2), [O(Ph2SiOSiPh2)O−]2Al2[O(Ph2SiOSiPh2)O]2 ⋅ 2 HN+Et3 (3 a, 3 b), which crystallizes in two different phases, and [O(Ph2SiOSiPh2)O−]2Al2[O(Ph2SiOSiPh2)O]2 ⋅ 2 HN+(CH2CH2)3N (4). As a common structural feature of these compounds two aluminum atoms which are incorporated in six-membered Al[O(SiPh2OSiPh2)O−] rings are connected as spiro cyclic centers through oxygen and/or siloxane bridges [(OSiPh2)nO] (n=1, 2) to form an assembly of three fused rings at the aluminum corners. The central ring is either eight- (1, 2) or twelve-membered (3, 4). Alkyl ammonium cations balance the charges and form hydrogen bridges to oxygen atoms of the six membered rings. The pentacyclic (Ph2SiO)8[Al(O)OH]4 (I) can be used indirectly (addition of water) and directly as chelating ligand versus Co(II)Cl and In-CH3 fragments as shown with the isolated and structurally characterized compounds (HN+Et3)2{[(Ph2Si)2O3]Al4(OH)4O22}2− (5 a, 5 b) and (Ph2SiO)8[AlO(OH)]2[AlO2]2(InCH3) ⋅ 2 O(CH2)4 (6).