Scandium siloxides

Scheme 6 Reaction of heterotrimetallic scandium siloxide (30) with AlMes...

Edelmann et al. recently reported the reaction behavior of the heterotrimetallic lithium-scandium-lithiiun siloxide (30) toward AJMes, GaMes, and InMes, respectively (Scheme 6). In case of excess AlMes, selective replacement of one of the hthium ions by a cationic AlMe2 unit occmred, rather than nucleophilic displacement of the chloride bound to scandium by a methyl group was observed. 

The molecular structure of the isolated product could unambiguously be identified by X-ray analysis as the heterotrimetallic lithimn-scandium aluminum siloxide (31). The selective formation of (31) is promising insofar as this synthetic strategy may open the door to the preparation of a wide variety of heterotrimetallic siloxides with perhaps interesting electronic and magnetic properties, from readily available salt adducts of rare earth siloxides. 

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