Cyclic Alumosiloxanes and Alumosilicates: Exemplifying the Loewenstein Rule at the Molecular Level

The cyclic alumosiloxane [{LAl(μ-O)(Ph2Si)(μ-O)}2] (3) and alumosilicate [{LAl(μ-O){(tBuO)2Si}(μ-O)}2] (4) were obtained by reaction of the appropriate R2Si(OH)2 precursor (R = Ph, OtBu) with [{LAl(H)}2(μ-O)] (1), providing a nice illustration of the Loewenstein rule at work at the molecular level.