Synthesis of Group 14 Metal Enamido, Alkenyl, Imido and Alkenyl‐Amido Complexes from a Monoanionic Pyridyl‐1‐azaallyl Ligand

Abstract

AbstractThe reactivity of the lithium pyridyl‐1‐azaallyl complex [Li{N(SiMe3)C(Ph)C(R)(C5H4N‐2)}]2 [R = SiMe3 (1) or H (10)] with group 14 metal halides has been studied under various conditions. It undergoes a salt‐elimination reaction with MCl2 (M = Ge, Sn or Pb) to form [Ge{C(C5H4N‐2)C(Ph)N(SiMe3)2}{N(SiMe3)C(Ph)C(SiMe3)(C5H4N‐2)}] (2), [M{N(SiMe3)C(Ph)C(SiMe3)(C5H4N‐2)}2] [M = Sn (3), Pb (4)], and [M{N(SiMe3)C(Ph)C(SiMe3)(C5H4N‐2)}Cl] [M = Ge (5), Sn (6), Pb (7)], where the azaaalyl moiety acts as a monodentate ligand. However, the reaction of 1 with GeCl4 or HSiCl3 forms [Ge{C(C5H4N‐2)C(Ph)N(SiMe3)}Cl2]2 (8) or [{(C5H4N‐2)C(SiMe3)C(Ph)N}(μ‐SiHCl)]2 (9), respectively, by elimination of both the lithium salt and Me3SiCl; the reaction of 10 with GeCl4 gives [{(C5H4N‐2)C(H)C(Ph)N}(μ‐GeCl2)]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)