Synthesis and Coordination Properties of Highly Preorganised Polyamine Macrocycles

摘要

Synthesis and characterisation of the new macrocyclic ligands L1-L4 are reported. The ligands present one or two pentaamine moieties, each contanining two piperazaine rings, linked by benzene or anthracene spacers. Interaction of L1 with H~+, Cu(II), Zn(II), Hg(II), and Pd(II) and of L3 with H`+, and Cu(II) has been studied by potentiometric titrations in 0.15 mol dm~(-3) NaCl aqueous solution at 298.1 (+-) 0.1 K. The thermodynamic data suggest that in the metal complexes only three nitrogen donor atoms bind each metal ion. As a consequence of the low coordination number, these complexes are promising receptors for different molecules.