Template synthesis, characterization and electrochemical studies of copper(II) macrocyclic complexes derived from 4-methyl-2,6-di(formyl/benzoyl)phenol and diamines

Copper(II) macrocyclic complexes [Cu(L)Cl-2]. 2H(2)O (1, 2) have been synthesized from the copper(II)-directed condensation of 4-methyl-2,6-diformylphenol (1) or 4-methyl-2,6-dibenzoylphenol (2) with diamines [1,2-diaminopropane (a), 1,3-diaminopropane (b) and o-phenylenediamine (c)] in EtOH in high yields. These complexes are monomeric, non-electrolytes and paramagnetic, indicating a distorted octahedral geometry around copper, which is supported by i.r., electronic, e.s.r. and magnetic susceptibility measurements. Electrochemical studies of (I) and (2) using c.v. indicate an irreversible cathodic peak (ca. -0.65 to -0.76 V) corresponding to reduction of copper(II) to copper(I) and the diffusion-controlled nature of the electrode process.