Germane vs. digermane formation

Abstract

Oxidative addition reactions of dialkylchalcogenanes R2E2 and [Me2Si(Nt-Bu)2]Ge 1 yielded bis(alkylchalcogeno)germanes Me2Si(Nt-Bu)2Ge(ER)2 (R = Et, E = S 2, Se 3; R = Me, E = Se 4) and digermanes [Me2Si(Nt-Bu)2Ge(EEt)]2 (E = S 5, Se 6). The reaction of 1 with Et2Te2 proceeds with formation of Me2Si(Nt-Bu)2Ge(TeEt)27, which slowly converts into the Te-bridged complex [Me2Si(Nt-Bu)2GeTe]28. 1-6 and 8 were characterized by single crystal X-ray diffraction.

Oxidative Addition of Diethylchalcogenanes to Lappert's Germylene and Stannylene

“…In sharp contrast to the reaction of the cyclic germylene Me 2 Si(N t ‐Bu) 2 Ge,13 bis[bis(trimethylsilyl]amido]germylene (Me 3 Si) 2 N) 2 Ge and ‐stannylene (Me 3 Si) 2 N) 2 Sn only react with E 2 Ph 2 with oxidative addition and formation of the corresponding germanes and stannanes (Me 3 Si) 2 N) 2 M ( E Ph) 2 ( M = Ge, Sn, E = S, Se, Te). This reaction behavior was expected since both compounds adopt monomeric structures in solution.…”

“…1 H and 13 C NMR spectra of the resulting products only showed the expected resonances due to the Et and N(SiMe 3 ) 2 groups in the expected 1:1 molar ratios, indicating the insertion of the germylene into the E–E bond with subsequent formation of the corresponding germanes. This is in remarkable contrast to the reactions between Et 2 E 2 and the cyclic germylene [Me 2 Si(N t Bu) 2 ]Ge, in which the digermanes [Me 2 Si(N t Bu) 2 Ge E Et] 2 , containing a direct Ge–Ge bond and the Ge atoms adopting the formal oxidation state +III, were unexpectedly formed in addition to the expected germanes [Me 2 Si(N t Bu) 2 ]Ge( E Et) 2 , in which the Ge atoms adopt the preferred formal oxidation state +IV 13. In addition, the 77 Se NMR and 127 Te NMR spectra of 2 and 3 also showed only a single resonance (Table 1).…”

“…We recently reported on reactions of the cyclic bis(amino)germylene [Me 2 Si(N t Bu) 2 ]Ge with dialkyldichalcogenanes R 2 E 2 ( E = S, Se, Te; R = Me, Et), which proceeded with formation of the expected germanium dichalcogenides Me 2 Si(N t Bu) 2 Ge( ER ) 2 and of the unexpected digermanes [Me 2 Si(N t Bu) 2 Ge( ER )] 2 , respectively 13. In order to further investigate this unexpected reaction behavior, we expanded our studies on analogous reactions of the acyclic bis[bis(trimethylsilyl]amido]germylene (Me 3 Si) 2 N) 2 Ge and the corresponding bis[bis(trimethylsilyl]amido]stannylene (Me 3 Si) 2 N) 2 Sn 14…”

Isolation and Structure of Germylene‐Germyliumylidenes Stabilized by N‐Heterocyclic Imines

“…[9] In analogy to B,T obita and co-workers synthesized the NHC-stabilized dicationic complexes of type C in which the repulsion between the two central germanium atoms is decreased by delocalization of apositive charge into the imidazoline rings ( Figure 1). [12] We reported the isolation of the imidazolin-2-iminosubstituted Ge II and Sn II monocations E containing af ourmembered EN 2 Si (E = Ge,S n) ring system ( Figure 1). Since the seminal report on monomeric bis(amido) germylene and stannylene comprising aE N 2 Si (E = Ge,S n, Pb) scaffold by Veith and co-workers (D,F igure 1), [11] ar apidly growing number of papers have been published concerning the research on N-heterocyclic metallylenes.…”

Isolation and Structure of Germylene‐Germyliumylidenes Stabilized by N‐Heterocyclic Imines

“…Interestingly,t he solid structure of D was not reported before 2014. [12] We reported the isolation of the imidazolin-2-iminosubstituted Ge II and Sn II monocations E containing af ourmembered EN 2 Si (E = Ge,S n) ring system ( Figure 1). Their formation is promoted by the delocalization of positive charge density into the imidazoline ring.…”