Macrocyclic tetraamido-N ligands that stabilize high-valent complexes of chromium, manganese, iron, cobalt, nickel, and copper

Two oxidatively resistant macrocyclic tetraamido-N ligands are shown to stabilize unusual high valent middle and later transition metal complexes of Cr, Mn, Fe, Co, Ni, and Cu.;Two Cr(V) monooxo complexes have been synthesized and characterized by X-ray crystallography, IR, and EPR. A novel, easily synthesized, stable, crystalline ;The first water-stable Mn(V) monooxo complex is described. It was characterized by ;The first mononuclear five-coordinate Fe(IV) complex to be isolated as a crystalline compound and characterized by X-ray crystallography is described. The Mossbauer spectrum obtained at 150 K has ;The synthesis of the first macrocyclic square planar Co(III) complex is described. Characterization includes ;The first crystallographically characterized neutral square planar complex of Co in an oxidation state higher than +II is reported. It is a stable, yet potent, oxidant which is soluble in benzene. The reversible redox couple is found at ca. 1.26 V vs. NHE in CH;The first square planar Ni(III) complex with an innocent ligand to be structurally characterized is described. EPR and UV-vis data indicate that the complex is also four-coordinate in solutions of noncoordinating solvents, and in noncoordinating glasses at 4 K. The EPR spectra are of significance to Ni bioinorganic chemistry since ;The synthesis of a Cu(III) complex with reversible cathodic and anodic waves is described. The Cu(III) complex has been crystallographically characterized.;The Dunitz amide nonplanarity analysis has been applied to the 13 crystal structures presented in order to illustrate the amide nonplanarity that occurs in some of the macrocyclic compounds.