Synthesis of Group 14 Metal Enamido, Alkenyl, Imido and Alkenyl-Amido Complexes from a Monoanionic Pyridyl-1-azaallyl Ligand
✍ Scribed by Wing-Por Leung; Cheuk-Wai So; Yuen-Sze Wu; Hung-Wing Li; Thomas C. W. Mak
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 226 KB
- Volume
- 2005
- Category
- Article
- ISSN
- 1434-1948
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✦ Synopsis
Abstract
The reactivity of the lithium pyridyl‐1‐azaallyl complex [Li{N(SiMe~3~)C(Ph)C(R)(C~5~H~4~N‐2)}]~2~ [R = SiMe~3~ (1) or H (10)] with group 14 metal halides has been studied under various conditions. It undergoes a salt‐elimination reaction with MCl~2~ (M = Ge, Sn or Pb) to form [Ge{C(C~5~H~4~N‐2)C(Ph)N(SiMe~3~)~2~}{N(SiMe~3~)C(Ph)C(SiMe~3~)(C~5~H~4~N‐2)}] (2), [M{N(SiMe~3~)C(Ph)C(SiMe~3~)(C~5~H~4~N‐2)}~2~] [M = Sn (3), Pb (4)], and [M{N(SiMe~3~)C(Ph)C(SiMe~3~)(C~5~H~4~N‐2)}Cl] [M = Ge (5), Sn (6), Pb (7)], where the azaaalyl moiety acts as a monodentate ligand. However, the reaction of 1 with GeCl~4~ or HSiCl~3~ forms [Ge{C(C~5~H~4~N‐2)C(Ph)N(SiMe~3~)}Cl~2~]~2~ (8) or [{(C~5~H~4~N‐2)C(SiMe~3~)C(Ph)N}(μ‐SiHCl)]~2~ (9), respectively, by elimination of both the lithium salt and Me~3~SiCl; the reaction of 10 with GeCl~4~ gives [{(C~5~H~4~N‐2)C(H)C(Ph)N}(μ‐GeCl~2~)]~2~ (11) in a similar manner. X‐ray structural analysis of compounds 2−5, 7−9 and 11 showed that the pyridyl‐1‐azaallyl ligand bonds to the metal center in enamido, alkenyl, alkenylamido, and imido bonding modes. A mechanism for the formation of these compounds is proposed and discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)