Diastereoselectively self-sorted low-symmetry binuclear metallomacrocycle and trinuclear metallocage.

A pyridine/aniline appended unsymmetrical bis-monodentate ligand -(3-aminophenyl)nicotinamide, is synthesized via condensation of nicotinic acid with excess -phenylene diamine. A low-symmetry binuclear complex of the PdL'L type and an extremely rare trinuclear complex of the PdL type are produced by self-assembly of the ligand with -protected palladium(II) (, PdL') and palladium(II), respectively. Two isomers ( [(2,0), (2,0)] and [(1,1), (1,1)]-forms) are theoretically possible for the PdL'L-type complex whereas nine isomers can be envisaged in the case of the PdL-type arrangement.