[(thf)₅Ln(Ge₉{Si(SiMe₃)₃}₂)] (Ln = Eu, Sm, Yb): Capping Metalloid Germanium Cluster with Lanthanides

Abstract

We report the synthesis of three neutral complexes with different coordination modes of a di-silylated metalloid germanium cluster to divalent lanthanides [(thf) 5 Ln(η n -Ge 9 (Hyp) 2 )] (Ln = Yb (1, n = 1); Eu (2, n = 2, 3), Sm (3, n = 2, 3); Hyp = Si(SiMe 3 ) 3 ) by the salt metathesis of LnI 2 with K 2 [Ge 9 (Hyp) 2 ] in THF. The complexes were characterized by elemental analysis, nuclear magnetic resonance and UV−vis−NIR spectroscopy, and single-crystal X-ray diffraction. In thf solution, the formation of contact or solvate-separated ion pairs depending on the concentration is assumed. Compound 2 exhibits a blue luminescence typical for Eu 2+ . The solid-state magnetic measurements of compounds 2 and 3 confirm the presence of divalent europium and samarium, respectively.

Metalloid germanium cluster shears for lanthanide diiodides

“…Thus, the Stokes shift can be estimated to be 80 nm. This value and that of the FWHM are typical for molecular Eu 2+ complexes 17 and especially close to the emission and excitation spectra of the recently reported europium complex with disubstituted germanium cluster ligand [(thf) 5 Eu(Ge 9 (Hyp) 2 )] 9 and EuI 2 in thf. 16,18…”

“…Thus, the Stokes shift can be estimated to be 80 nm. This value and that of the FWHM are typical for molecular Eu 2+ complexes 17 and especially close to the emission and excitation spectra of the recently reported europium complex with disubstituted germanium cluster ligand [(thf) 5 Eu(Ge 9 (Hyp) 2 )] 9 and EuI 2 in thf. 16,18 In order to asses these spectra we have measured the luminescence of EuI 2 and bis-ligand compound [(thf) 2 Eu (Ge 9 (Hyp) 3 ) 2 ] 5 under the same conditions (see ESI †).…”

“…Similar artefacts have been reported for related clusters very recently. 9 In conclusion, we have established the synthesis of ionic compounds with metalloid germanium cluster [Ge 9 (Hyp) 3)), (Hyp = Si(SiMe 3 ) 3 ). A new aspect of metalloid germanium cluster chemistry as weakly coordinating anion is observed, which in this case stabilizes uncommon lanthanideiodide chain structures even in the presence of thf.…”

“…In contrast to this, as we reported earlier, the disilylated dianionic germanium cluster [Ge 9 (Hyp) 2 ] 2− forms the neutral lanthanide complexes with direct coordination of Ge 9 -cluster to divalent lanthanides [(thf) 5 Ln(η n -Ge 9 (Hyp) 2 )] (Ln = Yb, n = 1; Ln = Sm, Eu, n = 2 and 3). 9 (Scheme 1, B–D )…”

A Series of Cyclopentadienyl Lanthanum Complexes with Metalloid Germanium Clusters

“…The latter ones have recently shown a new facet of metalloid germanium clusters, namely, activity in homogeneous catalysis. − In addition to η-coordination, some metal compounds lead to cluster expansion and the formation of closo clusters . Very recently, in our research group, a successful formation of complexes with f elements has been demonstrated …”