Unsymmetrical ligand complexes of CuII, NiII, and CoII derived from salicylaldehyde and 1,3-propanediamine with either pyridine-2-carbaldehyde or pyrrole-2-carbaldehyde

The 1 : 1 : 1 condensates of salicylaldehyde, propanediamine, and either pyrrole-2-carbaldehyde (L1) or pyridine-2-carbaldehyde (L2) have been isolated and combined with selected first-row transition-metal ions. The copper(II) and nickel(II) complexes of L1 have been prepared and characterized, as has the pyridine adduct of the corresponding cobalt(II) derivative. The copper(II) and nickel(II) complexes of L2 have also been characterized. Spectral and chemical properties of these systems are compared with those of complexes involving analogous symmetrical Schiff-base ligands.