A Hydrogen Bonded Aluminium Alkoxide Hydroxide Aggregate Resulting from the Exposure of Methylaluminium Dichloride to Air

Due to the practical and technical importance of aluminium alkyls, their behaviour towards the components of air is of fundamental interest. The interaction with dioxygen has been studied quite extensively over a period of several decades [1]. In a recent contribution to this field Lewiński and co-workers reported the insertion of oxygen into AlÐC bonds resulting in alkoxide aggregates, but also alkylperoxide complexes, which contain η2terminally bonded tBuOO groups at aluminium [2]. The reactions with aluminium alkyls with the humidity of air are also of great technical significance due to the use of alumoxanes as active cocatalysts in olefin polymerisation [3]. The reactions of organometallic group 13 compounds with water and the resulting molecular structures were recently reviewed by Roesky and coworkers [4]. Since the first structural characterisation of alkylalumoxanes [5] a variety of structural motifs of Al/O aggregates was found including those with bridging OH groups in alumoxane aggregates [6]. The two most frequently observed types of aggregation are shown in Scheme 1, exhibiting Al2O2 four-membered rings and Al3O3 six-membered rings.