A Bis(silylenyl)pyridine Zero‐Valent Germanium Complex and Its Remarkable Reactivity

Abstract

The synthesis, reactivity, and electronic structure of the unique germylone iron carbonyl complex [SiNSi]Ge →Fe(CO) is reported. The compound was obtained in 49 % yield from the reaction of the bis(N-heterocyclic silylenyl)pyridine pincer ligand SiNSi (1,6-C NH -[EtNSi(N Bu) CPh] ) with GeCl ⋅(dioxane) to give the corresponding chlorogermyliumylidene chloride precursor [SiNSi]Ge Cl Cl , which was further reduced with K Fe(CO) . Single-crystal X-ray diffraction analysis of [SiNSi]Ge→Fe(CO) revealed that the Ge center adopts a trigonal-pyramidal geometry with a Si-Ge-Si angle of 95.66(2)°. Remarkably, one of the Si donor atoms in the complex is five-coordinated because of additional (pyridine)N→Si coordination. Unexpectedly, the reaction of [SiNSi]Ge→Fe(CO) with GeCl ⋅(dioxane) (one molar equivalent) yielded the first push-pull germylone-germylene donor-acceptor complex, [SiNSi]Ge→GeCl →Fe(CO) through the insertion of GeCl into the dative Ge →Fe bond. The electronic features of the new compounds were investigated by DFT calculations.

Stereoselective Transfer Semi‐Hydrogenation of Alkynes to E‐Olefins with N‐Heterocyclic Silylene–Manganese Catalysts

“…The geometric situation is similar to those observed in the NHC‐Mn II complexes [MnCl 2 (C{N( i Pr)C(Me)} 2 ) 2 ] and [MnCl 2 (IMes) 2 ] (IMes=1,3‐dimesitylimidazol‐2‐ylidene) . However, akin to the situation in Fe II and Ge II complexes stabilized by L1 , the pyridine N atom in [L1]MnCl 2 is reluctant in coordinating to the Mn atom as indicated by the relatively long Mn(1)–N(1) distance of 3.259 Å. This is in contrast to PNP pincer‐type Mn II complexes with much shorter N(py)–Mn distances, which can be rationalized by the stronger σ‐donor strength of Si II versus P III towards Mn.…”

Tetrylones: An Intriguing Class of Monoatomic Zero‐valent Group 14 Compounds

“…Synthesis of germylone complexes 45 and 46. [42] Figure 32. Molecular structureso fgermylone complexes (a) 45 and (b) 46 (botha nions omitted for clarity).…”

“…While complexes 40 – 42 were prepared by the simple complexation of germylone 30 , iron complex 45 , which is the iron complex of germylone 44 , was synthesized by the simultaneous reduction and complexation of the precursor of the germylone (Scheme ). That is, the reaction of 43 , which was prepared by the reaction of the corresponding ligand with GeCl 2 ⋅dioxane, with K 2 [Fe(CO) 4 ] resulted in the formation of germylone complex 45 (Scheme ) . It was found that the pyridine moiety of 45 coordinates to one of the silylene moiety, forming its unsymmetrical structure.…”

“…That is, the reaction of 43,w hich was prepared by the reactiono ft he corresponding ligand with GeCl 2 ·dioxane, with K 2 [Fe(CO) 4 ]r esultedi nt he formationo f germylonec omplex 45 (Scheme 13). [42] It was found that the pyridine moietyo f45 coordinates to one of the silylene moiety, forming its unsymmetrical structure. Furthermore, treatment of 45 with GeCl 2 ·dioxane afforded the unique germylone-germylene-iron complex 46 ( Figure 32).…”

Reactivity of a coordinated inorganic acetylene unit, HBNH, and the azidoborane cation [HB(N3)]+

“…7,8 Unfortunately the use of these bulky substituents restricted access to the HBNH array by potential reagents/catalysts. In this Edge Article we introduce a more reactive HBNH adduct and describe our attempts to convert this species into LB·BN·LA complexes (LA = Lewis acid; LB = Lewis base; Scheme 1); in addition we investigate the reactivity of the donor-stabilized azidohydride boronium cation [BH(N 3 )] + .…”