Herein we report on the reactivity of the stable germanium(II) hydride LGeH (L = CH{(CMe)(2,6-iPr(2)C(6)H(3)N)}(2)) (2), which contains a low-valent germanium atom. 2 is prepared from the corresponding germanium(II) chloride LGeCl (1) using H(3)Al x NMe(3) or K[HB(iBu)(3)] in toluene. The reaction of 2 with carbon dioxide in toluene at room temperature affords a germanium(II) ester of formic acid, LGe-O-C(O)H (3), which is formed by insertion of the carbon dioxide into the germylene hydrogen bond. 2 also reacts with alkynes at room temperature to give the first germanium(II)-substituted alkenes (4, 5, and 6). These two reaction types have in common the fact that the hydrogen and germylene from LGeH are transferred to an unsaturated bond: the carbon-oxygen double bond (C=O) in the former case and the carbon-carbon triple bond (C[triple bond]C) in the latter. Moreover, the reaction of 2 with elemental sulfur in toluene at room temperature leads to the germanium dithiocarboxylic acid analogue LGe(S)SH (7). Compound 7 is formed by the unprecedented insertion of elemental sulfur into the germylene hydrogen bond and oxidative addition of elemental sulfur to the germanium(II) atom. This leads to the formal conversion of the GeH hydride to a SH proton. Compounds 3-7 were investigated by microanalysis, multinuclear NMR spectroscopy, and single-crystal X-ray structural analyses.

The reaction of LGeCl [1; L = CH{(CMe)(2,6-(i)Pr(2)C(6)H(3)N)}(2)] with 1,3-di-tert-butylimidazol-2-ylidene results in the formation of the germylene L'Ge [2; L' = CH{(C=CH(2))(CMe)(2,6-(i)Pr(2)C(6)H(3)N)(2)}]. 2 reacts with ammonia under N-H cleavage to give LGeNH(2) (3). This type of reaction can also be used to activate primary amines. 3 is characterized by microanalysis, multinuclear NMR spectroscopy, and X-ray structural analysis. The single-crystal X-ray structural analysis indicates 3 to be a monomer, and the germanium atom shows a trigonal-pyramidal environment with a stereochemically active lone pair.

A stable silicon(II) monohydride is accomplished through a covalent shared interaction of the silylene lone-pair and a sp(3)-hybridized boron atom of the Lewis acidic BH(3). Experimental charge density investigations reveal a central positively charged silicon atom bound to a negatively charged hydrogen atom. The positively charged H-Si-BH(3) moiety is coordinated by the lone-pairs of electrons of the benzamidinate ligand. This coordination is reinforced by a transannular Si1···C1 privileged exchange channel.

Dialkylamino compounds of group 14 elements (Si, Ge, Sn) in the +2 oxidation state supported by benzamidinate ligands were synthesized and treated with pentafluoropyridine. Two different modes of reactivity were observed, depending on the metal atom and the basicity of the substituent at the metal. Pentafluoropyridine undergoes oxidative addition reaction at the Si(II) and Ge(II) atoms whereas at the Sn(II) atom substitution of the NMe(2) group by the para fluorine of pentafluoropyridine occurs. The C-F bond activation by the lone pair of germanium is the first report of this kind. The Sn(II) fluoride obtained has an elongated Sn-F bond length and can be used as a good fluorinating agent. The compounds were characterized by multinuclear NMR spectroscopy, mass spectrometry, elemental analysis, and X-ray structural analysis. Single crystal X-ray structural analysis of the tin fluoride shows an asymmetric dimer with weak [Formula: see text] interactions.

A well-designed method for the preparation of a β-diketiminatolead(II) monofluoride has been developed using LPbNMe(2) (L = [CH{C(Me)(2,6-iPr(2)C(6)H(3)N)}(2)]) and pentafluoropyridine (C(5)F(5)N). The resulting LPbF was used for the synthesis of amidinatosilicon(II) monofluoride. Moreover the activation of a ketone was observed when the LPbF was treated with PhCOCF(3).