The Use of Five-Coordinate Aluminum Alkyls To Prepare Molecules Containing a Single Al−O−Si Linkage

The present work entails the synthesis and first structural characterization of complexes possessing a single Al−O−Si linkage. These are of the formula LAlOSiPh 3 (L = Salen( t Bu) ( N, N ‘-ethylenebis(3, 5-di- tert -butylsalicylideneimine)) ( 11 ); Salpen( t Bu) N, N ‘-propylenebis(3,5-di- tert -butylsalicylideneimine)) ( 12 ); Salophen( t Bu) ( N, N ‘-phenylenebis(3,5-di- tert -butylsalicylideneimine)) ( 13 ); and Salomphen( t Bu) ( N, N ‘-(3,4-dimethylphenylene)bis(3,5-di- tert -butylsalicylideneimine)) ( 14 ). They are formed by combining the novel five-coordinate aluminum alkyl starting materials L( t Bu)AlR (where L = Salen( t Bu), R = Me ( 1 ), Et ( 2 ), i Bu ( 3 ); Salpen( t Bu), R = Me ( 4 ), Salophen( t Bu) R = Me ( 5 ), Et ( 6 ), i Bu ( 7 ); and Salomphen, R = Me ( 8 ), Et ( 9 ), i Bu ( 10 )) with Ph 3 SiOH in toluene. All of the compounds were characterized spectroscopically and, in the case of 1, 10, 11, 12, and 13, by X-ray crystallography.