STOICHIOMETRIC AND CATALYTIC OXIDATIONS BY DINUCLEAR COPPER(I) AND COPPER(II) COMPLEXES OF A SCHIFF-BASE LIGAND DERIVED FROM THE 2 2-CONDENSATION OF PYRIDINE 2,6-DICARBOXALDEHYDE AND 1,5,9-TRIAZANONANE/

Dicopper(I) and dicopper(II) complexes of the macrocyclic ligand tadec a-1(32),2,11,13,15,17(34)18,27,29(33),3O-ene, (PD)(2)(DIPN)(2), were p repared and examined for their reactivities, The dioxygen complex of [ Cu-2(PD)(2)(DIPN)(2)](2+) was generated in solution and was found to c atalytically convert hydroquinone, t-butylhydroquinone, 2,6-di-t-butyl phenol, and 2,6-dimethoxyphenols to their respective oxidation product s, benzoquinone, t-butylbenzoquinone, 3,3',5,5'-tetra-t-butyldiphenoqu inone, 3,3',5,5'-tetramethoxydiphenoquinone. The substrates 3,5-di-t-b utylcatechol and 4-t-butylcatechol were converted to 3,5-di-t-butyl-1, 2-benzoquinone and the gamma-lactone of 3-hydroxy-4-t-butylmuconic aci d ester respectively whereas for 4-methylcatechol the complex was inac tive. The dicopper(II) complex of (PD)(2)(DIPN)(2), [Cu-2(PD)(2)(DIPN) (2)](4+) gave products with these substrates that were identical to th e products obtained with the Cu(I) dioxygen complex. In addition, 4-me thylcatechol was converted to the gamma-lactone of 3-hydroxy-4-methylm uconic acid eater. The oxidation of 3,5-di-t-butylcatechol by [Cu-2(PD )(2)(DIPN)(2)](2+) and dioxygen was found to be first order in the com plex. The oxygenated form of the complex [Cu-2(PD)(2)(DIPN)(2)](2+) wa s determined to be more effective (gave more turnovers) than oxygenate d forms of analogous dicopper(I) complexes of ligands prepared from fu ran-2,5-dicarboxaldehyde and 1,4,7-triazaheptane and from pyridine-2,6 -dicarboxaldehyde and 1,4,7-triazaheptane.