title: On the Reactivity of Silylated Ge9Clusters: Synthesis and Characterization of [ZnCp*(Ge9{Si(SiMe3)3}3)], [CuPiPr3(Ge9{Si(SiMe3)3}3)], and [(CuPiPr3)4{Ge9(SiPh3)2}2].
abstract: We report on the synthesis of new derivatives of silylated clusters of the type [Ge9(SiR3)3]-(R = SiMe3, Me = CH3; R = Ph, Ph = C6H5) as well as on their reactivity towards copper and zinc compounds. The silylated cluster compounds were synthesized by heterogeneous reactions starting from the Zintl phase K4Ge9. Reaction of K[Ge9{Si(SiMe3)3}3] with ZnCl2leads to the already known dimeric compound [Zn(Ge9{Si(SiMe3)3}3)2] (1), whereas upon the reaction with [ZnCp*2] the coordination of [ZnCp*]+to the cluster takes place (Cp*=1,2,3,4,5-pentamethylcyclopentadienyl) under the formation of [ZnCp*(Ge9{Si(SiMe3)3}3)] (2). A similar reaction leads to [CuPiPr3(Ge9{Si(SiMe3)3}3)] (3) from [CuPiPr3Cl] (iPr=isopropyl). Further we investigated the novel silylated cluster units [Ge9(SiPh3)3]-(4) and [Ge9(SiPh3)2]-(5), which could be identified by mass spectroscopy. Bis- and tris-silylated species can be synthesized by the respective stoichiometric reactions, and the products were characterized by ESI-MS and NMR experiments. These clusters show rather different reactivity. The reaction of the tris-silylated anion 4 with [CuPiPr3Cl] leads to [(CuPiPr3)3Ge9(SiPh3)2]+as shown from NMR experiments and to [(CuPiPr3)4{Ge9(SiPh3)2}2] (6), which was characterized by single-crystal X-ray diffraction. Compound 6 shows a new type of coordination of the Cu atoms to the silylated Zintl clusters.
authors.affiliation: Department Chemie, Technische Universität München, Lichtenbergstraße 4, 85747, Garching, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Mayer
authors.affiliation: Department Chemie, Technische Universität München, Lichtenbergstraße 4, 85747, Garching, Germany.
authors.forename: Lorenz J
authors.initials: LJ
authors.lastname: Schiegerl
authors.affiliation: Department Chemie, Technische Universität München, Lichtenbergstraße 4, 85747, Garching, Germany.
authors.forename: Thomas F
authors.identifier: http://orcid.org/0000-0001-9460-8882
authors.initials: TF
authors.lastname: Fässler
keywords: Zintl clusters; copper; germanium; silanes; zinc