A Base‐Stabilized Lead(I) Dimer and an Aromatic Plumbylidenide Anion

Abstract

Aromatische niedervalente Blei‐Analoga eines Indenylanions (siehe Schema; 1) werden durch SnCl2 unter Bildung des basestabilisierten Blei(I)‐Dimers 2 oxidiert. Die Reduktion von 2 mit Lithium führt wieder zu 1. Beide Spezies wurden NMR‐spektroskopisch und Röntgen‐ kristallographisch charakterisiert.

Access to Silicon(II)– and Germanium(II)–Indium Compounds

“…As expected, the adducts are Si NMR spectrum presumably due to the low solubility of the adducts and gradual decomposition to elemental indium. However, in the solid state, the 29 Si NMR chemical shift of 3 appears at δ −31.7 ppm, while 2 shows a broad signal ranging from −54.4 to −84.3 ppm, which are in good accordance with silylene adducts reported by Khan, Tacke, and others. 25,26,27a The appearance of two signals for the trimethylsilyl groups in 1 H (2, δ 0.56 and 0.65 ppm; 3, 0.50 and 0.60 ppm) as well as 29 Si NMR of 2 and 3 indicates that they are not equivalent, resulting from the hindered rotation due to the presence of the bulky substituents around the Si(II) atom.…”

“…However, in the solid state, the 29 Si NMR chemical shift of 3 appears at δ −31.7 ppm, while 2 shows a broad signal ranging from −54.4 to −84.3 ppm, which are in good accordance with silylene adducts reported by Khan, Tacke, and others. 25,26,27a The appearance of two signals for the trimethylsilyl groups in 1 H (2, δ 0.56 and 0.65 ppm; 3, 0.50 and 0.60 ppm) as well as 29 Si NMR of 2 and 3 indicates that they are not equivalent, resulting from the hindered rotation due to the presence of the bulky substituents around the Si(II) atom. Akin to 2 and 3, both 5 and 6 show two signals for the SiMe 3 moieties in their respective 1 H NMR spectra (5, δ 0.43 and 0.62 ppm; 6, 0.42 and 0.63 ppm).…”

“…34, 131.97, 129.16, 128.36, 127.18, 56.83, 31.69, 29.28, 5.64, 4.84 ppm. 29 Si CP/MAS NMR (25 °C): δ 11.4 (SiMe 3 ), 4.3 (SiMe 3 ), −54.4 to −84.3 (SiN(SiMe 3 ) 2 ). HRMS (CH 3 CN): m/z calcd for C 22 H 43 N 3 Cl 3 InSi 3 + Na + [M + Na] + 676.0761, found 676.0833.…”

“…14 Examples of carbonyl-free silylene complexes of 3d transition metals in the formal oxidation state +2 are now too frequent to be comprehensively listed, thanks to extensive investigations by the groups of H. Roesky, P. Roesky, Stalke, Driess, Tacke, Inoue, Khan, and many others. 15−26 The coverage of the s and p blocks is also expanding and is supplemented by examples of bonding to s-/p-block Lewis acids such as boron, 27 aluminum, 27 calcium, 28 germanium, 29 tin, 30 and lead. 30 However, when it comes to indium, there has only been one reaction reported between a Si(II) compound and an indium derivative.…”

Anorganische Chemie 2013

“…Der Blei‐Blei‐Abstand im Dimer ist mit 313 pm relativ groß. Wird das Reduktionsmittel im Überschuss und bei tiefer Temperatur eingesetzt, so entsteht ein aromatisches Plumbylidenid‐ion 74…”