Molecular species containing group 13 metal–nitrogen bonds

   Coordinate M^_N bond (M = heavier group 13 element) formation is exemplified in a number of complexes such as trans-[GaCl₂(py)₄]‏, and in)Me₂AlNMe₂(₂, which has a cyclic structure analogous to. Coordinate bond formation also gives a series of AlxNy cluster compoundsby reactions the structures of selected groups of clusters are shown in Figure 1.1, and the bonding in the Al_xN_y cages is rationalized in terms of localized schemes.

   A number of related Ga-containing cages are known, as well as a few Tl^_N clusters, e.g. Tl₂)MeSi(₂)NtBu(₄, as showen in below.

However, in the latter and related compounds, the Tl atoms do not carry terminal substituents, another manifestation of the thermodynamic 6s inert pair effect.

    Multiply-bonded compounds of the type observed for boron are not a feature of the later group 13 elements.