In contrast to the well-developed metal acetylides, the heavier analogues of the type REEM (E = Si, Ge, Sn, Pb; M = metals) have not been reported to date. Herein, we describe the synthesis of a silylenestabilized germanium analogue of alkynylaluminum ( 4) by the reaction of a silylene-stabilized digermavinylidene (3) with 0.25 equiv of (AlCp*) 4 in THF at 80 °C. The structure of 4 has been unambiguously characterized by spectroscopic analysis, X-ray diffraction analyses and DFT calculations, and features a linear AlGeGe skeleton with a Ge=Ge double bond and a polarized GeÀ Al bond. Complex 4 shows excellent reactivity towards small molecules such as H 2 , CS 2 and TolNCO, and this allows for the construction of the structurally intriguing germylenyl aluminum complex (5) and the germacycles (6, 7).

Monovalent group 15 cations L2Pn + (L = σ-donor ligands, Pn = N, P, As, Sb, Bi) have attracted significant experimental and theoretical interest because of their unusual electronic structures and growing synthetic potential. Herein, we describe the synthesis of a family of antimony(I) and bismuth(I) cations supported by a bis(silylene) ligand [(TBDSi2)Pn][BArF4] (TBD = 1, 8, 10, 9-triazaboradecalin; ArF = 3,5-CF3-C6H3; Pn = Sb, (2); Bi, (3)). The structures of 2 and 3 have been unambiguously characterized spectroscopically and by X-ray diffraction analysis and DFT calculations. They feature bis-coordinated Sb and Bi atoms which exhibit two lone pairs of electrons. The reactions of 2 and 3 with methyl trifluoromethane sulfonate provide a approach for the preparation of dicationic antimony(III) and bismuth(III) methyl complexes. Compounds 2 and 3 serve as 2e donors to group 6 metals (Cr, Mo), giving rise to ionic antimony and bismuth metal carbonyl complexes 6–9.

In contrast to the well-developed metal acetylides, the heavier analogues of the type REEM (E = Si, Ge, Sn, Pb; M = metals) have not been reported to date. Herein, we describe the synthesis of a silylenestabilized germanium analogue of alkynylaluminum ( 4) by the reaction of a silylene-stabilized digermavinylidene (3) with 0.25 equiv of (AlCp*) 4 in THF at 80 °C. The structure of 4 has been unambiguously characterized by spectroscopic analysis, X-ray diffraction analyses and DFT calculations, and features a linear AlGeGe skeleton with a Ge=Ge double bond and a polarized GeÀ Al bond. Complex 4 shows excellent reactivity towards small molecules such as H 2 , CS 2 and TolNCO, and this allows for the construction of the structurally intriguing germylenyl aluminum complex (5) and the germacycles (6, 7).