Metal-ion-directed synthesis of the new macrocyclic and acyclic homo- and heterodinuclear schiff base complexes derived from putrescine

Authors:

• Wanda Radecka-Paryzek,
• Małgorzata Teresa Kaczmarek,
• E. Luks,
• Izabela Maria Pospieszna-Markiewicz

Abstract

The template reaction of 2,6-diacetylpyridine with putrescine, a biogenic diamine, in the presence of lanthanum(III) and zinc(II) ions produces homo- and heteronuclear complexes of 22-membered macrocyclic ligand with an N₆ set of donor atoms as a result of the [2+2] Schiff base cyclocondensation. Complexes containing Schiff base acyclic ligands terminated by two carbonyl groups or one carbonyl and one amine group as products of the partial metal-promoted condensation have been also isolated. They might be regarded as possible intermediates in the formation of the macrocyclic complexes. The complexes have been characterized by spectral data (IR, ¹H NMR, ESI-MS) and elemental analyses.