Early-Transition-Metal Complexes of Functionalized Nonagermanide Clusters: Synthesis and Characterization of [Cp2(MeCN)Ti(η1‑Ge9{Si(TMS)3}3)] and K3[Cp2Ti(η1‑Ge9{Si(TMS)3}2)2]

Anionic clusters with a homoatomic [Ge9] core are species with Ge atoms in low oxidation states. In this study their reaction with early-transition-metal complexes was investigated. We report the syntheses of Ti­(III) complexes of silylated [Ge9] Zintl clusters, which are rare examples of molecular complexes with Ge–Ti interactions. The neutral species [Cp2(MeCN)­Ti­(η1-Ge9{Si­(TMS)3}3)] (1) was obtained by the reaction of K­[Ge9{Si­(TMS)3}3] with [Cp2TiCl]2 in toluene as dark orange crystals, whereas the reaction of K2[Ge9{Si­(TMS)3}2] with [Cp2TiCl]2 in thf and subsequent recrystallization from toluene resulted in dark green crystals of K3[Cp2Ti­(η1-Ge9{Si­(TMS)3}2)2] (2). Compound 2 contains the trianion [Cp2Ti­(η1-Ge9{Si­(TMS)3}2)2]3– (2a), which can be described either as a [Cp2Ti]+-bridged [Ge9{Si­(TMS)3}2]2– dimer or as a heavily distorted tetrahedral Ti­(III) complex bearing two germanide cluster ligands. Both compounds display donor–acceptor interactions between single Ge vertex atoms of the [Ge9] clusters and Ti­(III). Compounds 1 and 2 were characterized by single-crystal X-ray diffraction, EPR spectroscopy, and elemental analysis.