Tetraamido macrocyclic ligands

Chanda, A. Popescu, D. L. Tiago de Oliveira, F. Bominaar, E. L. Ryabov, A. D. Miinck, E. Collins, T. J. High-valent iron complexes with tetraamido macrocyclic ligands ... 

FIGURE 1.3 Ligands used in various biomimetic catalytic systems, (a) Pydic = 2,6-pyridinedicar-boxylic acid (Beller) (b) TAML = tetraamido macrocyclic ligand = 3,3,6,6,9,9-hexamethyl-3,4, 8,9-tetrahydro-lH-l,4,8,ll-benzotetraazacyclotridecine-2,5,7,10(6H,llH)-tetraone (Que) (c) mep = N,N -dimethyl-N,N -bis(2-pyridylmethyl)-ethane (Jacobsen) and (d) phen = phenanthroline (Stack). 

Several interesting bleach catalysts are described in recent patent literature and are currently under evaluation. Fe-TAML (tetraamido macrocyclic ligand), for example, was selected from a large number of similar tetraamido complexes, and has excellent dye transfer inhibition properties, as it selectively destroys many dyes dissolved in the wash liquor [37]. The catalyst is being tested in several applications, such as effluent bleaching, the pulp and paper industry, desulfurization of diesel, and decontamination [38]. 

Total degradation of fenitrothion and other organophosphorus pesticides by catalytic oxidation employing tetraamido macrocyclic ligands Fe-TAML (67) peroxide activations has been elaborated (Scheme 12). ... 

Horwitz et al. developed nonheme iron complexes with tetraamido macrocyclic ligands (TAML) that are efficient for the dye bleaching reactions with HjOj in water from neutral to basic Pinacyanol chloride as a reference,... 

Some examples of water-soluble ligands that have been used in catalytic oxidations with oxygen or hydrogen peroxide are shown in Fig. 7.1. Because much of this research falls into the category of biomimetic oxidations, water-soluble porphyrins and the structurally related phthalocyanines and other tetradentate nitrogen ligands, such as the tetraamido macrocyclic ligand (TAML), have been widely used. 

Liao RZ, LiXC, Siegbahn PEM. Reaction mechanism of water oxidation catalyzed by iron tetraamido macrocyclic ligand complexes—a DPT study. Em J Inorg Chem. 2014 728-741. 

Attempts to achieve macrocycles that are capable of stabilizing highly oxidized transition metal complexes has led to the design of noninnocent ligands. The structures of high-valent chrominm(V) oxo species with the two tetraamido N ligands (36) and (37) were determined. Both stmctnres were found to contain distinctly nonplanar amide gronps, and in (36) all fonr amides are nonplanar. 

Collins TJ, Slebodnick C, Uffelman ES. 1990. Cr(V)-oxo complexes of macrocyclic tetraamido-N ligands tailored for highly oxidized middle transition metal complexes. Inorg Chem 29(18) 3433-3436. 

A number of other recent studies have reported the use of EPR to examine the reaction mechanisms of nonheme iron complexes for catalytic oxidation, including iron complexes bearing a tetraamido macro-cycle, a 2,6-diacylpyridine ligand, a salen type ligand and the porphyrin macrocycle (Scheme in these studies, EPR was used as a... 

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