New side-bridged bismacrocycles and cross-bridged macrotricycles. Syntheses and Cu(ii) complexation study

Abstract

Eight new cyclen based constrained macropolycycles (4a–4d, 5a–5d) have been obtained by reductive ring cleavage of polyaminal derivatives of bis-macrocycles or macrotricyclic polyammonium salts by sodium borohydride. The mononuclear and dinuclear Cu(II) complexes of these macropolycyclic ligands were isolated as solids and investigated by UV-Vis and EPR spectroscopies. The possibility to obtain the specific formation of mononuclear complexes constitutes an original feature of these new macropolycycles.