title: Formation of tri- and tetranuclear titanacycles through decamethyltitanocene-mediated intermolecular C-C coupling of dinitriles.
abstract: The reactions of [Cp*2 Ti(η(2) -Me3 SiC2 SiMe3 )] (Cp*=η(5) -pentamethylcyclopentadienyl) with various dicyano compounds were investigated. Nitrile-nitrile CC couplings result in multinuclear complexes owing to the bifunctionality of the substrates. Applying 1,3- or 1,4-dicyanobenzene led to tri- and tetranuclear complexes of the rare 1-metalla-2,5-diaza-cyclopenta-2,4-dienes. These are potential catalysts and were tested in the ring-opening polymerization of ε-caprolactone. The reaction with adiponitrile as alkyl dinitrile afforded a trinuclear 1-metalla-2,5-diaza-cyclopent-3-ene through additional protonation of the nitrogen atoms. The structure and bonding of the products were investigated by X-ray crystallography and DFT analysis to understand the molecular organization in the macrocycles.
authors.affiliation: Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Straße 29a, 18059 Rostock (Germany).
authors.forename: Lisanne
authors.initials: L
authors.lastname: Becker
authors.forename: Perdita
authors.initials: P
authors.lastname: Arndt
authors.forename: Anke
authors.initials: A
authors.lastname: Spannenberg
authors.forename: Haijun
authors.initials: H
authors.lastname: Jiao
authors.forename: Uwe
authors.initials: U
authors.lastname: Rosenthal
keywords: CC coupling; macrocycles; metallacycles; nitriles; titanocene