Preparation and separation of asymmetric tripodal iron complexes of tren and selected aldehydes

The reaction of iron salts with the Schiff bases formed from the condensation of tren and mixtures of 2-pyridinecarboxaldehyde and 6-methyl-2-pyridinecarboxaldehyde, salicylaldehyde and 2-hydroxy-5-methylbenzaldehyde, salicylaldehyde and pyrrole-2-carboxaldehyde, or salicylaldehyde and 4-methyl-5-imidazolecarboxaldehyde affords a mixture of complexes that can be represented as [FetrenLxL′y]z (x +y = 3). In the case of salicylaldehyde and 4-methyl-5-imidazolecarboxaldehyde it is possible to separate the mixture with ion exchange chromatography.