A preconstrained tricyclic biimidazoline ligand adaptable to diverse coordination modes

The tricyclic biimidazoline ligand L possesses a preconstrained synperiplanar bisamidine N=C–C=N and has been shown to have a versatile coordination chemistry. In its manganese(II) tris-chelate complex [MnL3](ClO4)2, a distorted trigonal prismatic coordination geometry is adopted. By contrast, a square–planar copper(II) complex, [CuL3](ClO4)2 features one chelating as well as two monodentate L’s. In a third variation, an exclusively α-diimine-bridged dicopper unit is found in both the copper(I) [Cu2L3](BF4)2 and copper(II) [Cu2L4](ClO4)4 dimeric complexes.