Monoanionic tin oligomers featuring Sn-Sn or Sn-Pb bonds: Synthesis and characterization of a tris(triheteroarylstannyl)stannate and -plumbate

Abstract

The reaction of the lithium tris(2-pyridyl)stannate [LiSn(2-py6OtBu)3] (py6OtBu = C5H3N-6-OtBu), 1, with the element(II) amides E[N(SiMe3)2]2 (E = Sn, Pb) afforded complexes [LiE[Sn(2-py6OtBu)3]3] for E = Sn (2) and E = Pb (3), which reveal three Sn-E bonds each. Compounds 2 and 3 have been characterized by solution NMR spectroscopy and X-ray crystallographic studies. Large 1J(119Sn-119/117Sn) as well as 1J(207Pb-119/117Sn) coupling constants confirm their structural integrity in solution. However, contrary to 2, complex 3 slowly disintegrates in solution to give elemental lead and the hexaheteroarylditin [Sn(2-py6OtBu)3]2 (4).