N-Heterocyclic Carbene, Carbodiphosphorane And Diphosphine Adducts Of Beryllium Dihalides: Synthesis, Characterisation And Reduction Studies

Reaction of several N-heterocyclic carbenes, a carbodiphosphorane, and bis(diphenylphosphino)ethane (DPPE) with [BeX2(OEt2)(2)] (X = Br or I) have yielded a variety of beryllium dihalide adduct complexes, all of which were crystallographically characterised. Attempts to reduce the compounds to low oxidation state beryllium complexes using a variety of reducing agents have been carried out, but were of limited success. However, reaction of [(IPr)BeBr2] (IPr = :C{(DipNCH)(2)}; Dip = 2,6-diisopropylphenyl) with the aluminium(i) heterocycle, [:Al((Dip)Nacnac)] ((Dip)Nacnac = [HC(MeCNDip)(2)](-)) afforded the adduct complex, [{(IPr)(Br)Be(mu-H)}(2)], while reduction of [(IPr)BeBr2] with potassium naphthalenide gave the beryllium naphthalenediyl complex, [(IPr)Be(C10H8)]. Furthermore, reaction of [{(DPPE)BeI2}(infinity)], with [:Al((Dip)Nacnac)] led to insertion of the Al centre of the heterocycle into a Be-I bond, and formation of a rare example of an Al-Be bonded complex, [(DPPE)(i)Be-Al(i)((Dip)Nacnac)].