Alkoxyalumoxanes

The reaction of aluminum alkoxide or aluminum metal in primary alcohols at 250-300 degrees C was examined, and the products were characterized by powd er X-ray diffraction, IR spectroscopy, MAS NMR spectroscopy, thermal analys es, and scanning electron microscopy. The products had the layer structure of boehmite with alkyl pendant groups derived from the solvent alcohols, th e alkyl moieties of the aluminum alkoxide being completely expelled from th e product, and the basal spacing linearly increased with the carbon number of the alcohol. The alkyl groups were stable beyond the boiling point of th e parent alcohol, suggesting that they are covalently bonded to the boehmit e layers. All of the data suggest that the products are the alkyl derivativ es of boehmite (alkoxyalumoxanes) having an empirical formula of AlO(OH)((1 -x))(OR)(x). The value x depended on the alcohol used as the solvent and va ried from 0.62 to 0.21. Partial decomposition of alkyl moieties still prese rved the overall structure of alkoxyalumoxane.