The synthesis and characterization of new stable divalent
germanium, tin, and lead
homoleptic species (ArO)2M: (Ar =
2,4,6-[(CH3)2NCH2]3C6H2;
M = Ge (2), Sn (3), Pb (4))
are
described. 2
−
4 were obtained in
good yields by alcoholysis of the M−N bonds of the
divalent
precursors [(Me3Si)2N]2M by
ArOH. However, the direct reaction of 2 equiv of
[2,4,6-tris((dimethylamino)methyl)phenoxy]lithium trimer
(1) with the divalent species MCl2
resulted
in the formation of 2
−
4 in lower
yields along with the cluster
Li5(ArO)2Cl3. The
coordination
behavior of the (dimethylamino)methyl side chains toward the metal
atom was studied by
variable-temperature NMR spectroscopy; on the NMR time scale
2 in solution exhibits a
temperature-dependent N···M···N coordination mode. The
chemistry of 2
−
4 is
illustrated
through their reactions with diphenylethanedione, 1,2- and
1,4-benzoquinones, and triazolinedione.