Manganese complexes macrocyclic ligands

Mn(II) ions complexed by porphyrinato(2 ) ligands have shown catalytic superoxide anion dismutation. One SOD mimic, M40403, complexes Mn(II) via a macrocyclic ligand, 1,4,7,10,13-pentaazacyclopentadecane, containing added bis(cyclohexyl) and pyridyl functionalities. M40403 carries the systematic name [manganese(II) dichloro] 4R,9R, 14/s, 19/ )-3,10,13,20,26-pentaazatetracyclo[20.3. 1.0(4,9)0(14,19)]hexacosa-l(26),-22(23),24-triene ]. The molecule is shown in... 

The synthesis of the manganese(III) complex of the hexaaza macrocyclic ligand (176), derived from 2,3-butanedione and diethylenetriamine, and its use as a catalyst for the epoxidation of olefins using iodosylbenzene as oxidant has been reported." ... 

Other aza-donor macrocyclic ligand complexes of manganese(II) have been synthesized using metal template procedures." ... 

Macrocyclic complexes of type [M11LX2] (where L = (190) and X = C1, Br, I, and NCS) have been synthesized." These complexes appeared exceptionally stable relative to other manganese(II) phosphine complexes. They can be manipulated in air for minutes without decomposition, a finding that was ascribed to the steric protection afforded by this macrocyclic ligand species. 

Tab. 2 Electrochemical data for manganese complexes with porphyrins, Schiff bases, and related macrocyclic ligands in nonaqueous media...

Riley DP, Weiss RH. Manganese macrocyclic ligand complexes as mimics of superoxide dismutase. J Am Chem Soc 1994 116 387-8. 

Low-molecular-weight catalysts which mimic a natural enzymic function syn-Zymes) have potential utility for the treatment of diseases characterized by the overproduction of a potentially deleterious metabolic by-product or foreign gene product. The discovery and development of pentaaza macrocyclic ligand complexes of manganese(II) as functional mimics of superoxide dismutase (SOD) enzymes and their potential utility as human pharmaceutical agents is described. 

From our initial structure-activity relationship (SAR) studies, we have discovered that a class of manganese(II)-based complexes, I, incorporating the macrocyclic ligand 1,4,7,10,13-pentaazacyclopentadecane (where R can be any number of defined substituents with known stereochemistry), effectively catalyze the dismu-tation of superoxide. ... 

The synthesis and X-ray crystal structure of the macrocyclic bisphosphine oxide manganese complex (75) have been reported. A stable P-bonded phosphinidene oxide complex (77) of rhenium (1) has been prepared from (76) by nitrogen replacement with C-tertiarybutylphosphaalkyne followed by hydrolysis. 1 X-Ray crystallography was used to determine the structure of (77). What is reported to be the first complex (78) with a PO ligand has been prepared. 2 The molecular structure of (78), determined by X-ray crystallography, shows an exceptionally short PP distance. 

In the case of aliphatic triamines, (1-1-1) template condensation can be achieved if the number of atoms separating terminal NH2 groups equals 7. Thus, by interaction of dipropylenetriamine with dap on manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) matrices, it is possible to synthesise the 14-membered macrocyclic ligand L695 as appropriate complexes (Eq. 3.30) [71, 72, 74-76]. 

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