Sterically non-hindering endocyclic ligands of the bi-isoquinoline family.

Bi-isoquinoline can be used as a building block to prepare a new family of non-sterically hindering chelates, including a macrocyclic system; the endocyclic nature of the ligands has been confirmed by the X-ray structure of an octahedral tris-chelate iron(II) complex, which shows that the three chelates are easily accommodated in the coordination sphere of the metal in spite of their crescent shape.