Synthesis and Reactivity Studies of Amido‐Substituted Germanium(I)/Tin(I) Dimers and Clusters

Abstract

Three amide ligands of varying steric bulk and electronic properties were utilized to prepare a series of amido‐germanium(II)/tin(II) halide compounds, (LEX)n, (L= ‐N{B(DipNCH)2}(SiMe3), TBoL; ‐N{B(DipNCH)2}(SiPh3), PhBoL; ‐N(Dip)(tBu), DBuL; Dip=C6H3iPr2‐2,6; E=Ge or Sn; X=Cl or Br; n=1 or 2). Reductions of these with a magnesium(I) dimer, {(MesNacnac)Mg}2 (MesNacnac=[(MesNCMe)2CH]−, Mes=mesityl), afforded singly bonded amido‐digermynes (TBoLGe−GeTBoL and PhBoLGe−GePhBoL), and an amido‐distannyne (PhBoLSn−SnPhBoL), in addition to several low‐valent, amido stabilized tetrel–tetrel bonded cluster compounds, (DBuLGe)4, (DBuLSn)6 and Sn5(TBoL)4. The nature of the products resulting from these reactions was largely dependent on the steric bulk of the amide ligand employed. Cluster (DBuLGe)4 possessed an unusual folded butterfly structure, the bonding and electronic of which were examined using DFT calculations. Reactions of the amido‐germanium(I) compounds with H2 were explored, and gave rise to the amido‐digermene, TBoL(H)Ge=Ge(H)TBoL and the cyclotetragermane, {DBuL(H)Ge}4. Reactions of (DBuLGe)4 with a series of unsaturated small molecule substrates yielded DBuLGeOGeDBuL, DBuLGe(μ‐C2H4)2GeDBuL and DBuLGe(μ‐1,4‐C6H8)(μ‐1,2‐C6H8)GeDBuL. The latter results imply that (DBuLGe)4 can act as a masked source of the digermyne DBuLGeGeDBuL in these reactions. All further reactivity studies indicated that the germanium(I) compounds exhibit a “transition‐metal‐like” behavior, which is closely related to that previously described for bulky digermynes and related compounds.

Inorganic Benzene Valence Isomers

“…The reduction of the amido-tin(II) bromide precursor with the magnesium(I) dimer [( Mes NacNac) Mg] 2 ( Mes NacNac = [(MesNCMe) 2 CH] À ) gave rise to the Sn 6 (NtBuDip) 6 II-Sn3 (Scheme 22). [67] All SnÀ Sn distances (2.811-2.941 Å) in II-Sn1 and II-Sn2 are slightly longer than the sum of the single-bond covalent radii of two Sn atoms (2.80 Å). [68] The SnÀ Sn bonds in II-Sn1 are longer compared with those in II-Sn2, due to the bulky substituents (Table 6).…”

“…In 2019, Jones and coworkers reported the isolation of a twisted hexastannaprismane. The reduction of the amido‐tin(II) bromide precursor with the magnesium(I) dimer [( Mes NacNac)Mg] 2 ( Mes NacNac=[(MesNCMe) 2 CH] − ) gave rise to the Sn 6 (NtBuDip) 6 II‐Sn3 (Scheme ) …”

Reversible alkene binding and allylic C–H activation with an aluminium(i) complex

“…In 2009, following an unusual account of stannylene binding to a strained alkyne,19 Power and co-workers documented the first reversible addition of ethylene to a distannyne complex 20. Subsequently, the reactions of alkenes with digallynes,21 digermynes,22–24 silylenes,25,26 low-valent magnesium( i ) reagents,27 and a diazadiborinine have been reported 28. In all but the diazadiborinine system, the alkene scope is limited to ≤2 examples.…”

Influence of monomer deformation on the competition between two types of σ-holes in tetrel bonds

“…Tetrel bonds, described as "the tendency of heavier tetrel atoms to interact with anions or electron rich atoms" 70 belong to this family of σ-hole bonds, and have benefited from recent study, both theoretically and experimentally. [71][72][73][74][75][76][77][78][79] As a very recent example, calculations of the TH3 + (T = C, Si, Ge) complexes with H2 showed that H2 can serve as a tetrel bond acceptor through its σbond, and that the fundamental nature of the TH5 + depends on the identity of the T atom. It has also recently been reported that an S•••Sn contact plays a crucial role in activation of peroxisome proliferator-activated receptors (PPARs) by organotin molecules.…”