Trigonal prismatic metal complexes: a not so rare coordination geometry?

The solid state structures of two metal complexes of a hexaamine macrobicyclic ligand, in which the metal ion has an exact trigonal prismatic geometry, have been determined. Theoretical calculations showed this is the most stable geometry for d0, d10 and high spin d5 metal complexes of the ligand with M-N bond distances \u3e∼2.35 Å