Synthesis of stable diphenyl-di(germylene) and diphenyl-di(plumbylene)

Recent advances in the chemistry of isolable carbene analogues with group 13-15 elements

Carbenes (R2C:), compounds with a divalent carbon atom containing only six valence shell electrons, have evolved into a broader class with the replacement of the carbene carbon or the RC moiety with main group elements, leading to the creation of main group carbene analogues. These analogues, mirroring the electronic structure of carbenes (a lone pair of electrons and an empty orbital), demonstrate unique reactivity. Over the last three decades, this area has seen substantial advancements, paralleling the innovations in carbene chemistry. Recent studies have revealed a spectrum of unique carbene analogues, such as monocoordinate aluminylenes, nitrenes, and bismuthinidenes, notable for their extraordinary properties and diverse reactivity, offering promising applications in small molecule activation. This review delves into the isolable main group carbene analogues that are in the forefront from 2010 and beyond, spanning elements from group 13 (B, Al, Ga, In, and Tl), group 14 (Si, Ge, Sn, and Pb) and group 15 (N, P, As, Sb, and Bi). Specifically, this review focuses on the potential amphiphilic species that possess both lone pairs of electrons and vacant orbitals. We detail their comprehensive synthesis and stabilization strategies, outlining the reactivity arising from their distinct structural characteristics.

Synthesis, Characterization, and Reaction of Digermylenes

A series of digermylenes R(EGeL)2 (L=CH[C(Me)N(Ar)]2 , Ar=2,6-iPr2 C6 H3 ; E=O, R=1,3-C6 H4 (1), 1,4-C6 H4 (2), Me2 C(CH2 )2 (3); E=NH, R=1,4-C6 H4 (4), 1,4-C6 H10 (5); E=C(O)O, R=1,3-C6 H4 (6)) were synthesized by the reactions of L'Ge (L'=HC[C(CH2 )N(Ar)]C(Me)N(Ar), Ar=2,6-iPr2 C6 H3 ) with selected diphenols, diol, diamines, and o-/m-phthalic acids, respectively. Treatment of digermylene 1,3-C6 H4 (OGeL)2 (1) with sulfur, selenium and CuX (X=Cl, Br, I) led to the formation of 1,3-C6 H4 [OGe(S)L]2 (8), 1,3-C6 H4 [OGe(Se)L]2 (9), and (CuX)2 [1,3-C6 H4 (OGeL)2 ]2 (X=Cl (10), Br (11), I (12)), respectively. The obtained products were characterized by melting point, elemental analysis, FT-IR, 1 H and 13 C NMR spectroscopy, and single-crystal X-ray diffraction.

An α-diiminato germylene family: syntheses, structures, and reactivity towards C-C coupled digermylene and digermylene oxide

The synthesis and reactivity of a rigid α-diiminate ligand supported chlorogermylene 2 was demonstrated. The reaction of 2 with hydride donor K[BH(sBu)3] yielded a hydride addition product, a five-membered 6π-aromatic...

Bulky arene-bridged bis(amide) and bis(amidinate) complexes of germanium(II) and tin(II)

Several new, very bulky arene-bridged bis(amine) (viz. 1,3- and 1,4-{N(H)(SiPri3)}2(μ-C6H4), L1H2 and L2H2, respectively) and bis(amidine) pro-ligands (viz. 4,6-{[Dip(H)N](DipN)C}2(μ-DBF), DBF = dibenzofurandiyl, L3H2; and 1,3-{Ar†N(H)C(But)N}2(μ-C6H4), Ar† = C6H2{C(H)Ph2}2Pri-2,6,4, L4H2) have been developed. All can be doubly deprotonated with LiBun. The resultant dilithium salts react with either GeCl2·(dioxane) or SnBr2 to yield a series of amidotetrelylenecyclophanes (:E(μ-L1)2E: and :E(μ-L2)2E:, E = Ge or Sn) and bis(halotetrelylene) complexes (:E(X)(μ-L3)(X)E:, E = Ge or Sn, X = Cl or Br; and :Ge(Cl)(μ-L4)(Cl)Ge:). Reduction of :Ge(Cl)(μ-L4)(Cl)Ge: with KC8 afforded the crystallographically characterised bis(amido/amidinatogermylene) compound, :Ge(μ-L4)2Ge:, which is believed to have formed via a disproportionation process.