CRYSTAL-STRUCTURES OF THE LITHIUM CRYPTATES OF 2 MACROBICYCLIC LIGANDS CONTAINING PYRIDINE, BIPYRIDINE, AND BIISOQUINOLINE UNITS

The crystal structures of the LiBr complexes of two macrobicyclic ligands, [py.py.bpy] 1 and [py.biqi.biqi]2, have been determined. They confirm the cryptate nature of these species. In 3, the Li+ cation is bound in the shallow cavity of a ligand of flattened shape, whereas in 4, it is buried inside the macrobicycle and surrounded by its three bridges.