On the Variable Reactivity of Phosphine‐Functionalized [Ge₉] Clusters: Zintl Cluster‐Substituted Phosphines or Phosphine‐Substituted Zintl Clusters

Abstract

The reaction of [(Ge {Si(TMS) } PtBu )] with NHC CuCl yields [(Ge {Si(TMS) } )(tBu P)]Cu(NHC ) (1), which is a new derivative of the recently reported monomeric zwitterionic tetrel cluster compounds [(Ge {Si(TMS) } )(tBu P)]M(NHC ) (M: Cu, Ag, Au). By contrast, the reaction of the same anion [(Ge {Si(TMS) } PtBu )] with the more labile copper phosphine complex Cy PCuCl leads to the formation of [Ge {Si(TMS) } {(tBu) PCu} Ge {Si(TMS) } ] (2), which is a neutral dimeric twofold-bridged [Ge ] cluster compound, with the exo-bonded phosphine substituent being involved in the cluster bridging. In case of the presence of sterically more demanding phosphines in [Ge {Si(TMS) } PR ] [R: Mes (3) and NiPr (4)], reactions with NHC CuCl yielded the complexes NHC Cu[η -Ge {Si(TMS) } (PR )] [R: Mes (5) and NiPr (6)], comprising exclusively Cu-Ge bonds. Compounds 5 and 6 show varying reactivity in dependence of the identity of the phosphine group and represent the first examples of fourfold-substituted [Ge ] clusters with three different ligands bound to the [Ge ] cluster core. All compounds were characterized by H, C, P, and Si NMR spectroscopy. Additionally, compounds 3 and 4 were analyzed by ESI-MS, and the structures of compounds 1, 2, and 5 were characterized by single-crystal X-ray diffraction.

The influence of the FeCp(CO)2+moiety on the dynamics of the metalloid [Ge9(Si(SiMe3)3)3]−cluster in thf: synthesis and characterization by time-resolved absorption spectroscopy

“…All organic solvents were freshly distilled under nitrogen prior to use. Bruker DRX-250, ASX-300, AV-400 and AVII-500 spectrometers were used to obtain 1 H, 13 C, and 29 Si NMR spectra. 1 H, 13…”

“…10) is obtained via this synthetic route by varying the experimental conditions. The latter opened the door to "mixed"-substituted clusters like [Ge 9 (Hyp) 2 (HypPh)] − (HypPh = Si(SiMe 3 ) 2 (SiPh 3 ), 9 [Ge 9 (HypPh) 2 (Hyp)] − , 11 [Ge 9 (Hyp) 2 (PtBu 2 Cu-NHCDipp)] − , 12 [Ge 9 (Hyp) 2 (PtBu 2 )] − , 13 [Ge 9 (Hyp) 2 (SiPh 2 -CHvCH 2 )] − (ref. 14) and connected Ge 9 (Hyp) 2 units in [(Hyp) 2 Ge 9 -Me 2 Si-C 6 H 4 -SiMe 2 -Ge 9 (Hyp) 2 K] − .…”

Synthesis and Reactivity of Multiple Phosphine‐Functionalized Nonagermanide Clusters

“…The two [NHC Dipp Cu] + moieties coordinate to the triangular faces of the [Ge 9 ] core. Cu2 coordinates to Ge7 to Ge9 with nearly similar Cu‐Ge distances between 2.4241(5) Å (Ge1‐Cu1) and 2.5654(5) Å (Ge9‐Cu2), which are in the range of known values,,, whereas Cu1 coordinates the opposite triangular face with significantly shorter and longer distances of 2.3674(5) Å (Ge3‐Cu1) to 2.6873(6) Å (Ge2‐Cu1). As a result the coordination of Cu1 and Cu2 by the NHC ligands and the centres of gravity of the Ge 3 faces significantly deviates from linearity [∡(ctp1‐Cu1‐C1)=166.6(1)° or ∡(ctp2‐Cu2‐C28)=170.4(1)° with ctp1: centre of gravity of Ge1 to Ge3 and ctp2: centre of gravity of Ge7 to Ge9] and the NHC Dipp ligands are tilted toward the Cr(CO) 5 coordinated site of the cluster.…”

Boranyl‐Functionalized [Ge9] Clusters: Providing the Idea of Intramolecular Ge/B Frustrated Lewis Pairs

“…In previous studies we found that neutral species with a [NHC Dipp Cu] + moiety as the fourth substituent crystallized much more easily than the respective anionic species [6, 20] . Since the isolation of single‐crystalline material suitable for structure determination was not possible from the isolated solids, we carried out subsequent reactions of 1 a‐K to 3 a‐K with NHC Dipp CuCl (Scheme 2 b).…”