The planar ligand is ambidentate, showing a tridentate side
with two pyridine moieties and one anionic amide-type nitrogen
donor set and a bidentate dicarbonylic one. The N-type coordination
is appropriate for binding d metal ions, while the O-type one
is, in principle, accessible for binding oxofile lanthanide ions.[45]
The bis(2-pyridylcarbonyl)amine anion forms mononuclear complexes
with divalent and trivalent metal ions: MnII [46], FeII [47],
CuII [46], CrIII, FeIII and CoIII [48], RhII and RhIII [49]. The
[Mq(bpca)2]q2 complexes show compressed octahedral structures,
close to the D2d symmetry. A synopsis containing the ligand structure,
the pattern of the complex with view along the z axis, revealing
the mutually perpendicular ligand planes and the LF sequence
in the compressed octahedron with D2d symmetry, is presented in
the Scheme 2.