Template synthesis, structural and biological studies of new tetraazamacrocyclic complexes of lead(II)

This paper decribes the synthesis and characterization of several new tetraazamacrocyclic complexes of Pb(ll). The template condensation of adipic acid with primary diamines, be., ethylenediamine and propylenediamine in the presence of lead salts resulted in the formation of macrocyclic complexes. The geometry and the mode of bonding of the resulting complexes have been inferred from chemical analysis, IR and (HNMR)-H-1 spectral studies, molecular weight determinations and conductivity measurements. An octahedral geometry around the lead ion is suggested for the [(PbMac(n))X-2] (X = Cl, NO3 or CH,COO) complex. Based on molecular weight determinations and conductivity measurements, their monomeric and non-electrolytic nature has been confirmed, The biological activities of all the lead salts and their metal complexes have been studied by screening the compounds against organisms such as, E. coli, S. aureus, F: oxysporum and A. alternata and the results have been compared.