Synthesis and structural characterisation of low-valent Group 14 metal complexes containing tridentate 2,6-pyridyl-bridged bis (1-azaallyl) ligands

Treatment of GeCl2(dioxane), SnCl2 and PbCl2 with appropriate alkali-metal compounds containing 2,6-pyridyl-bridged bis(1-azaallyl) dianionic ligands afforded bivalent Group 14 metal compounds [M{{N(SiMe3)C(R)CH}2C5H3N-2,6}][R = Ph, M = Ge (1), Sn (2) and Pb (3); R = But, M = Sn (4) and Pb (5)]. The structures of the monomeric complexes 1, 2, 3 and 5 have been confirmed by single-crystal X-ray structure determination; it has been shown that the 2,6-pyridyl-bridged bis(1-azaallyl) ligand is bonded to the metal centre in a N,N,N-chelate fashion.