title: A monotopic aluminum telluride with an Al=Te double bond stabilized by N-heterocyclic carbenes.
abstract: Aluminum chalcogenides are mostly encountered in the form of bulk aluminum oxides that are structurally diverse but typically consist of networks with high lattice energy in which the chalcogen atoms bridge the metal centres. This makes their molecular congeners difficult to synthesize because of a pronounced tendency for oligomerization. Here we describe the isolation of the monotopic aluminum chalcogenide (L(Dip)N)AlTe(L(Et))2 (L(Dip)=1,3-(2,6-diisopropylphenyl)-imidazolin-2-imine, L(Et)=1,3-diethyl-4,5-dimethyl-imidazolin-2-ylidene). Unique features of (L(Dip)N)AlTe(L(Et))2 are the terminal position of the tellurium atom, the shortest aluminum-tellurium distance hitherto reported for a molecular complex and the highest bond order reported for an interaction between these elements, to the best of our knowledge. At elevated temperature (L(Dip)N)AlTe(L(Et))2 equilibrates with dimeric {(L(Dip)N)AlTe(L(Et))}2 in which the chalcogen atoms assume their common role as bridges between the metal centres. These findings demonstrate that (L(Dip)N)AlTe(L(Et))2 comprises the elusive Al=Te double bond in the form of an N-heterocyclic carbene-stabilized species.
authors.affiliation: Institut für Chemie, Anorganische und Analytische Chemie, Technische Universität Berlin, Straße des 17 Juni 135, Sekr. C2, 10623 Berlin, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Franz
authors.affiliation: Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szent Gellért tér 4, 1111 Budapest, Hungary.
authors.forename: Tibor
authors.initials: T
authors.lastname: Szilvási
authors.affiliation: Institut für Chemie, Anorganische und Analytische Chemie, Technische Universität Berlin, Straße des 17 Juni 135, Sekr. C2, 10623 Berlin, Germany.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Irran
authors.affiliation: Institut für Chemie, Anorganische und Analytische Chemie, Technische Universität Berlin, Straße des 17 Juni 135, Sekr. C2, 10623 Berlin, Germany.
authors.forename: Shigeyoshi
authors.initials: S
authors.lastname: Inoue