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 Si(II)-Ge(II) 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.

The activation of B-H and B-Cl bonds in boranes by base-stabilized low-valent silicon compounds is described. The reaction of the amidinato amidosilylene-borane adduct [L{Ar(MeSi)N}SiBH] [1; L = PhC(N tBu), and Ar = 2,6- iPrCH] with MeOTf in toluene at room temperature formed [L{Ar(MeSi)N}SiBHOTf] (2). [LSiN(SiMe)Ar] in compound 2 then underwent a B-H bond activation with BHOTf in refluxing toluene to afford the B-H bond activation product [LB(H)Si(H)(OTf){N(SiMe)Ar}] (3). On the other hand, when compound 2 was reacted with 4-dimethylaminopyridine in refluxing toluene, another B-H bond activation product [(μ-κ1:κ1-L)B(H)(DMAP)Si(H){N(Ar)SiMe}]OTf (4) was afforded. Mechanistic studies show that "(μ-κ1:κ1-L)B(H)(OTf)Si(H){N(Ar)SiMe}" (2A) is the key intermediate in the reactions mentioned above. The formation of 2A is further evidenced by the activation of the B-Cl bond in PhBCl by the amidinato silicon(I) dimer [LSi:] to form the B-Cl bond activation product [(μ-κ1:κ1-L)B(Cl)(Ph)Si(Cl)] (6). Compounds 2-4 and 6 were characterized by nuclear magnetic resonance spectroscopy and X-ray crystallography.

The coordination chemistry of an amidinato silylene and germylene toward group 14 element(ii) halides is described. The reaction of the amidinato silicon(ii) amide [LSiN(SiMe)] (1, L = PhC(NtBu)) with SnCl and PbBr afforded the amidinato silylene-dichlorostannylene and -dibromoplumbylene adducts [L{(MeSi)N}SiEX] (E = Sn, X = Cl (2); E = Pb, X = Br (3)), respectively, in which there is a lone pair of electrons on the Sn(ii) and Pb(ii) atoms. X-ray crystallography, NMR spectroscopy and theoretical studies show conclusively that the Si(ii)-E(ii) bonds are donor-acceptor interactions. Similar electronic structures were found in the amidinato germylene-dichlorogermylene and -dichlorostannylene adducts [L{(MeSi)N}GeECl] (E = Ge (5), Sn (6)), which were prepared by treatment of the amidinato germanium(ii) amide [LGeN(SiMe)] (4) with GeCl·dioxane and SnCl, respectively.

The background of the Frontispiece graphic shows the hive at Nanyang Technological University, which was designed by Thomas Heatherwick. It aims to promote interaction among professors and students. This philosophy is also demonstrated in the Communication by M.‐D. Su, C.‐W. So et al. on page 14329 ff. The interaction between the low‐valent silicon and cobalt centers in the dimeric amidinato cobaltosilylene resulted in promoting the regio‐ and stereoselective addition of the ortho‐C−H bond in arylpyridines with the C≡C triple bonds in alkynes.

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.