title: Polyalkynylanthracenes--syntheses, structures and their behaviour towards UV irradiation.
abstract: A series of bis- and tris[(trimethylsilyl)ethynyl]anthracenes (1,5-, 1,8-, 9,10- and 1,8,10-) has been synthesised by multistep (cross coupling) reactions and the behaviour of the SiMe3-functionalised alkynylanthracene derivatives towards UV irradiation was qualitatively studied by NMR spectroscopy. In the case of 9,10-bis[(trimethylsilyl)ethynyl]anthracene we observed a photodimerisation upon UV irradiation; the third example was reported for a symmetrically 9,10-difunctionalised anthracene derivative, besides those with small fluorine- and methyl-substituents. The anthracene dimerisation is completely thermally reversible and the temperature dependence of the cycloelimination reaction was studied by (1)H VT-NMR experiments. The (deprotected) 1,5- and 1,8-diethynylanthracenes were converted with (dimethylamino)trimethylstannane to obtain the corresponding SnMe3-functionalised alkynes, potentially useful as highly conjugated building blocks in Stille cross coupling reactions. The new anthracene compounds were completely characterised by multinuclear NMR spectroscopy, (high resolution) mass spectrometry and - in most cases - by X-ray diffraction experiments.
authors.affiliation: Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie, Centrum für Molekulare Materialien CM2, Universitätsstraße 25, D-33615 Bielefeld, Germany. mitzel@uni-bielefeld.de.
authors.forename: Jan-Hendrik
authors.initials: JH
authors.lastname: Lamm
authors.forename: Johanna
authors.initials: J
authors.lastname: Glatthor
authors.forename: Jan-Henrik
authors.initials: JH
authors.lastname: Weddeling
authors.forename: Andreas
authors.initials: A
authors.lastname: Mix
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