An N‐Heterocyclic Silylene‐Stabilized Digermanium(0) Complex

Abstract

The synthesis of an N‐heterocyclic silylene‐stabilized digermanium(0) complex is described. The reaction of the amidinate‐stabilized silicon(II) amide [LSiN(SiMe3)2] (1; L=PhC(NtBu)2) with GeCl2⋅dioxane in toluene afforded the SiII–GeII adduct [L{(Me3Si)2N}Si→GeCl2] (2). Reaction of the adduct with two equivalents of KC8 in toluene at room temperature afforded the N‐heterocyclic carbene silylene‐stabilized digermanium(0) complex [L{(Me3Si)2N}Si→ GeGe←Si{N(SiMe3)2}L] (3). X‐ray crystallography and theoretical studies show conclusively that the N‐heterocyclic silylenes stabilize the singlet digermanium(0) moiety by a weak synergic donor–acceptor interaction.

Bonding Relationship between Silicon and Germanium with Group 13 and Heavier Elements of Groups 14–16

“…The Ge=Ge bond lengths in 28 (2.3490(8) Å), a NHC adduct of germanium(0) [34] and in 29 (2.3518(16) Å), a NHSi adduct of digermanium(0) [35] are comparable, whereas the Ge=Ge bond length in phosphine‐stabilized digermavinylidene 37 (2.30597(19) Å) is slightly shorter than boryl substituted germavinylidene 33 (2.312(1) Å). The complexes 29 and 28 have a trans ‐bent geometry: SiGeGeSi skeleton (Si−Ge1−Ge2 91.95(6)°) [35] and [IPr→Ge=Ge←IPr] (C−Ge1−Ge2 89.87(8)°), [34] respectively.…”

“…The Ge=Ge bond lengths in 28 (2.3490(8) Å), a NHC adduct of germanium(0) [34] and in 29 (2.3518(16) Å), a NHSi adduct of digermanium(0) [35] are comparable, whereas the Ge=Ge bond length in phosphine‐stabilized digermavinylidene 37 (2.30597(19) Å) is slightly shorter than boryl substituted germavinylidene 33 (2.312(1) Å). The complexes 29 and 28 have a trans ‐bent geometry: SiGeGeSi skeleton (Si−Ge1−Ge2 91.95(6)°) [35] and [IPr→Ge=Ge←IPr] (C−Ge1−Ge2 89.87(8)°), [34] respectively. However, the four atoms (Ge1, Ge2, B1 and B2) in 33 (B1−Ge1−Ge2: 108.5(1)°, B1−Ge1−B2: 142.6(1)°, B2−Ge1−Ge2: 108.9(1)°), and the five atoms (C2, C3, P, Ge2, and Ge1) in 37 (C1−Ge1−C2: 108.3(1)°, C2−Ge1−Ge2: 113.6(1)°, C1−Ge1−Ge2: 136.9(1)°, Ge2−P−C3: 115.4(1)°, P−C3−C2: 115.8(1)°, C3−C2−Ge1: 115.0(1)°, Ge1−Ge2−P: 80.210(10)°) are lie within a single plane (Table 3).…”

“…Protection from NHCs is a developed approach to synthesize stable multiple bonded compounds. Recently, Frenking, jones and co‐workers (in 2009) [34] and Yim, So and co‐workers (in 2013) [35] for the first time isolated NHC stabilized dimeric germanium(0) complex ( 28 ) and NHSi ligands stabilized germanium(0) dimer {: Ge=Ge :} complex ( 29 ), respectively (Figure 1).…”

“…In 2019, Wesemann and co-workers reported the synthesis and isolation of digermavinylidene complex, stabilized by phosphine. [38] The reaction of GeCl 2 •dioxane (35) with germylene-phosphine adduct yielded chloro substituted germyl-germylene complex (36). [39] The reduction of 36 with sodium or [(HC(MeCMesN) 2 )Mg] 2 (Mes = 2,4,6-Me 3 C 6 H 2 ) gave complex 37 as red crystals in good yield (72% using Mg(I) as reducing agent and 52% via Na as reducing agent; Scheme 16).…”

Donor‐Stabilized Silylene/Phosphine‐Supported Carbon(0) Center with High Electron Density

“…[19,20] Thes ignificantly enhanced stability of the corresponding metal complexes IX,compared to those with base-free silylene ligands, enables application of such silicon-based ligands in catalysis. [21,22] However,i ns pite of the growing number of DSStransition metal complexes (IX), [19,23] the use of the DSSs VIII as ligands for the stabilization of main-group elements in their zero-oxidation-state is still scarce.Afew exceptions are DSSstabilized digermanium(0) (X) [24] and germanium(0) (XI) [25] complexes recently reported by the groups of So and Apeloig and Driess,r espectively.H erein we report the synthesis of an ew carbon(0) complex (XII)f eaturing ap hosphine and aDSS ligand, and it can also be regarded as adonor-stabilized 1-silavinylidene phosphorane.O fp articular interest, this complex exhibits ac arbon(0) center with an exceptionally high electron density resulting from the strongly electrondonating DSS ligand.…”