Monoanionic Tin Oligomers Featuring Sn–Sn or Sn–Pb Bonds: Synthesis and Characterization of a Tris(Triheteroarylstannyl)Stannate and -Plumbate

The reaction of the lithium tris(2-pyridyl)stannate [LiSn(2-py)3] (py6OtBu = C5H3N-6-OtBu), 1, with the element(II) amides E{N(SiMe3)2}2 (E = Sn, Pb) afforded complexes [LiE{Sn(2-py)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-py)3]2 (4).