Main group pyridyl-based ligands; strategies to mixed metal complexes.

Tris-2-pyridyl ligands of the type [Y(2-py)(3)](n-) containing metallic or semi-metallic bridgehead atoms (Y) are a relatively new innovation in the area of main group coordination chemistry. This review highlights the major classes of ligands currently available, compares their coordination chemistry to their more well known non-metallic counterparts and explores the way in which they can be used to form heterometallic complexes in a targeted way.