Schiff base macrocyclic ligands, copper

One of the earliest Schiff base macrocycles to exhibit a haemocyanine-like structure was the copper(II) perchlorate complex of 5.5 which binds readily to azide or hydroxide.8 The azide complex exhibits two square pyramidal copper binding domains with the basal plane occupied by one pyridyl nitrogen atom and two imine functionalities as well as a terminal azide ligand. The apices of the two pyramidal coordination polyhedra are linked by a single bridging azide anion. Continuing the biomimetic theme, manganese (II) cascade complexes of the unsymmetrical 5.6 have... 

Macrocyclic Ligands. The structure of LCu2Cl2,6H20 [LH2 = quadridentate Schiff base macrocycle (111) formed by condensation of propane-l,3 diamine and 2-hydroxy-5-methylisophthalaldehyde] has been determined. The cyclic structure consists of two copper atoms held in a dinuclear arrangement (112) by the planar N4O2 donor set ... 

ABSTRACT. The application of tetraimine Schiff base macrocycles as ligands in the modelling of di- and trinuclear copper(I) and copper(II) biosites and dinuclear manganese(II) biosites is discussed. 

Bailey, N. A., Fenton, D. E., Moody, R., etal., Complexes of ligands providing endogenous bridges A. copper(II) complexes of macrocyclic Schiff-bases derived from 2,6-diacetylpyridine and l,N-diamino-N -hydroxyalkanes (N,N = 3,2 - 4,2 - and 5,3) - synthesis, properties, and structures. J. Chem. Soc., Dalton Trans. 1987, 2519-2529. 

The examined compound behaves as an N,Te-donor ligand also in analogous cobalt and copper complexes [922]. The N,Te-ligand environment is very likely for complexes 530 [923], 531 [924], adduct 532 [925], and tellurium-containing macrocyclic Schiff bases 533 [926] ... 

Although the term dynamical combinatorial chemistry has only been coined at the end of the last century, the template effect has been used for a much longer time. Some of the best known macrocyclic ligands such as cyclam probably would not have been known so well if their synthesis had not implied the template effect. Probably the first example of a metal ion template for the formation of imino-macrocycles N. F. Curtis, D. A. House, Structure of some aliphatic Schiff-base complexes of nickel (II) and copper (II), Chem. and End., 1961, 42, 1708-1709. 

Dioxygen binding in a dinuclear copper(I)-complex, based on a macrocyclic tetra Schiff base ligand 11, was reported by Martell and co-workers (scheme 5). 

The reactions of nickel(II) and copper(II) amino complexes with acetone have been studied extensively. Condensation reactions of coordinated amines with acetone proceed relatively easily, but further reactions follow. The initially formed complexes, which contain Schiff bases, undergo intramolecular rearrangements to form complexes containing macrocyclic ligands. Scheme 11.15. This reaction is the basis for the synthesis of a large number of macrocyclic ligands. 

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