title: Dialkylaluminium-, -gallium-, and -indium-based poly-Lewis acids with a 1,8-diethynylanthracene backbone.
abstract: Potential host systems based on a rigid 1,8-diethynylanthracendiyl backbone were synthesised by treatment of 1,8-diethynylanthracene with the Group 13 trialkyls AlMe(3), GaMe(3), InMe(3), AlEt(3) and GaEt(3). The resulting products were characterised by IR and multinuclear NMR spectroscopy, elemental analyses and determination of their crystal structures by X-ray diffraction. The compounds are dimeric in the solid state and comprise two M(2)C(2) heterocycles. Depending on the steric demand of the alkyl substituents at the metal atom, different types of binding modes were observed, which can be classified to lie between the ideals of side-on coordination with almost linear primary M-C≡C units and the 3c-2e coordination with symmetrically bridging alkynyl units in M-C-M bonds. As a solution in THF the dimers are broken into monomers and some are found to undergo ligand scrambling reactions.
authors.affiliation: Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie, Universität Bielefeld, Universitätsstraße 25, 33615 Bielefeld, Germany.
authors.forename: Jasmin
authors.initials: J
authors.lastname: Chmiel
authors.forename: Beate
authors.initials: B
authors.lastname: Neumann
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Stammler
authors.forename: Norbert W
authors.initials: NW
authors.lastname: Mitzel