Chiral, enantiopure, aluminum(III) and titanium(IV) azatranes

Al-III and Ti-IV complexes of C-3-symmetric tetradentate trisamidoamme ligands with trigonal bipyramidal coordination geometry, containing chlorine or dialkylamido groups, or with a free coordination site in the apical position, have been synthesised by salt metathesis and amine elimination. Products with threefold symmetry were generally obtained for tetravalent titanium, whereas for the aluminium complexes either asymmetric structures with two of the three podand arms taking part in coordination to the metal or symmetric arrangements possessing the full threefold symmetry were formed depending on the steric properties of the ligands.