Homo- and heteroalumoxane silicates

Abstract

Homo- or hetero alumoxanesilicates or bridged M–OH–M hydroxidesilicates with unusual or unprecedented inorganic cores have been obtained in reactions between 1 and nBuLi, AlMe3, GaMe3 or ZnMe2. The aluminum derivatives serve as models for MAO.

Hydrolysis of organometallic and metal–amide precursors: synthesis routes to oxo-bridged heterometallic complexes, metal-oxo clusters and metal oxide nanoparticles

“…14). 133 In all cases, the Si−OH proton displayed greater Brønsted acidity than the Al−OH proton, which may be partly due to the steric bulk of the dipp groups providing steric protection for the Al−OH unit. In this competition system, the Si−OH unit was either deprotonated before Al−OH, or was the only OH group to be deprotonated.…”

Structural Similarity in a Series of Alkali Metal Aluminates with Heteroleptic tert‐Butoxide–Isobutyl Ligand Sets

“…There are several reported methods for synthesising heterobimetallic aluminium alkoxides. These include reaction of preformed lithium aluminates with a parent alcohol, [35] reaction of a pre-formed aluminium alkoxide with nBuLi, [36] lithiation of a parent alcohol and reaction of the generated lithium alkoxide in turn with either an alkylaluminium or aluminium alkoxide reagent, [37] or reaction of a parent alcohol with the base Li-AlH 4 . [38] In 2002, Gordon and Watkin successfully synthesised two mixed-metal samarium-aluminium alkoxides on reacting iBu 3 Al with Sm(HMDS) 3 {HMDS = 1,1,1,3,3,3-hexamethyldisilazide, [N(SiMe 3 ) 2 ]}, followed by the addition of alcohol (iPrOH or tBuOH).…”

Siloxyaluminate and Siloxygallate Complexes as Models for Framework and Partially Hydrolyzed Framework Sites in Zeolites and Zeotypes

“…A dimeric hydroxyaluminate compound, {Li[Al{C[Si(Me) 3 ] 3 }(O i Pr) 2 (OH)]} 2 , displayed a slightly shorter Al−OH distance of 1.738(7) Å and much longer Li−OH distance of 1.97(2) Å [63] . A NacNac‐supported Al(μ‐OH)(μ‐O)Si(μ‐OLi)(O t Bu) 2 ] 2 dimeric cluster has a slightly shortened Al−OH and elongated Li−OH bond, with an Al−OH bond length of 1.738(2) and a Li−OH bond length of 1.871(4) Å as compared to 10 [64] . In yet another dimeric analogue containing Al−O(H)−Li linkages, both bonds are elongated relative to 10 at 1.790(3) and 1.964(7)/1.980(7) Å for Al−OH and Li−OH, respectively [65] .…”

“…[63] AN acNac-supported Al(m-OH)(m-O)Si(m-OLi)(OtBu) 2 ] 2 dimericc lusterh as as lightly shortened AlÀOH and elongated LiÀOH bond, with an AlÀOH bond length of 1.738(2) and aL i ÀOH bond length of 1.871(4) as compared to 10. [64] In yet another dimeric analogue containing AlÀO(H)ÀLi linkages, both bonds are elongated relative to 10 at 1.790(3) and 1.964(7)/1.980(7) for AlÀOH and LiÀOH, respectively. [65] Based on thesec omparisons, the bond lengths measured for 10 are consistent with relatively strongi nteractions betweent he hydroxide and both Al and Li, with some elongation of the AlÀOH(Li)r elative to at erminal AlÀOH [65] bond.…”