'Mono and Binuclear Complexes of Schiff-Base Macrocyclic and Related Ligands: Synthetic and Structural Studies'.

Template condensation of the diketones, 2,6-diacetylpyridine and 2,5-diformyl-furan with a series of diprimary amines has yielded a range of binucleating macrocyclic ligands with potential internuclear separation between ~7.5 and 3^. The cations used to generate the (2 + 2) con2+ + densation product include Gp (II) metal ions, Pb and Ag . Complexes of these ions and of first transition series ions, obtained by transmetallation, have been structurally characterized using electronic, infrared, n.m.r and e.s.r spectroscopy. In a few cases X-ray crystallographic structure determination has been carried out (collaboration with Dr MGB Drew at the University of Reading). Mononuclear complexes, could be made either with the large and flexible ligands or with the smallest ligands; in one case as the result of a ring- opening reaction. Binuclear transition metal complexes were obtained with all the macrocycles studied. The degree of spin-spin interaction between the metal centres in the paramagnetic binuclear complexes varied with internuclear distance and the nature and disposition of the bridging ligand, if present. Some simple substrate oxidations have been studied using the diCu 0) complex of a 30-membered macrocycle as catalyst.; diCu(l) complexes of related acyclic ligands have been prepared and examined to discover whether they might also have potentially useful catalyst properties. The binuclear chemistry of Cu (I) has also been studied in complexes of a heterocyclic a-diimine ligand where an unusual mode of coordination has been shown to exist