Homo- and heteroalumoxane silicatesElectronic supplementary information (ESI) available. CCDC 1423189-1423195 and 1433277. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c5ra18481a

Acid-base reactions of L Al(OH)(μ-O)Si(OH)(O t Bu) 2 ( L = HC[CMeNAr] 2 − , Ar = 2,6-iPr 2 C 6 H 3 ) ( 1 ) with n BuLi, AlMe 3 , GaMe 3 , and ZnMe 2 led to the isolation of several homo and heterometallic systems containing either the hydroxo Al-OH-M or alumoxane Al-O-M unit stabilized by a silicate moiety. In reactions with AlMe 3 , the stepwise deprotonation of 1 could be observed and leads to the first example of a covalent Al 2 SiO 3 alumoxane ring and furthermore the multimetallic compounds L Al(μ-O)(μ-AlMe 2 )(μ-O)Si[(μ 3 -O)(AlMe 2 )](μ-O t Bu)(O t Bu) and L Al(μ 3 -O)(AlMe 3 )(μ-AlMe 2 )(μ-O)Si[(μ 3 -O)(AlMe 2 )](μ-O t Bu)(O t Bu) are formed in the presence of two or more equivalents of AlMe 3 . These compounds represent molecular models for a "pure" and "real" MAO and a rare case of a "free" AlMe 3 molecule coordinated to an alumoxane moiety. The molecular structures of all compounds have been determined using single crystal X-ray diffraction. Homo- or hetero alumoxanesilicates or bridged M-OH-M hydroxidesilicates with unusual or unprecedented inorganic cores have been obtained in reactions between 1 and n BuLi, AlMe 3 , GaMe 3 or ZnMe 2 . The aluminum derivatives serve as models for MAO.