Iron salen-type

The solubility properties of salen-type complexes can be tailored by employing substituents such as t-butyl and triphenylphosphonium-methyl (—CFl2PPh3+), with its associated chloride, in the aromatic rings.The stability constant for A,A -o-phenylenebis(salicylideneimine)-iron(III) in 80% (w/w) DMSO-water has been compared with stability constants for complexes of six metal ions with this ligand. 

Finally, iron catalysts based on salen-type ligands have been used. These iron(III)-salen complexes were regarded as enzyme models, using PhIO as oxidant (Scheme 3.52) [162]. Initially, the corresponding active iron-oxo complexes were formed by reaction with PhIO and isolated before use. A stoichiometric amount of the iron-oxo complex allowed the efficient oxidation of a variety of aryl methyl sulfides in moderate to good yields. 

It was found that iron phthalocyanine and the Co(II)-complexes of salen-type molecules, especially the Co(II)-complex of N,N -bis(salicylidene)-l,2-phenylenediamine (salophen) activated efficiently the molecular oxygen in the catalytic system. 

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... 

A characteristic feature is the formation of oxo and/or hydroxo bridges.42 Binu-clear systems may be (a) doubly bridged and (b) singly bridged with a linear or bent FeOFe. The bent ones are known with 4-, 5-, and 6-coordinate iron(III) an example is [(salen)Fe]2(/x-0). Porphyrin and phthalocyanine complexes are linear bridged species of the type (porph Fe)2/x-X where X = O, N, and C. 

Z. Gaillon, N. Sajot, F. Bedioui, J. Devynck, and KJ. Balkus, Jr, Electrochemistry of Zeolite Encapsulated Complexes. Part 3. Characterization of Iron and Manganese SALEN Entrapped in Y Faujasite Type Zeolite. J. Electroanal. Chem., 1993, 345, 157-167. 

The electropolymerization method of functional monomers has proved successful in many cases, in particular to incorporate various ligands and their metallic complexes, like salen [66,245], porphyrin [246], diphosphine [247], pyridine [71,80,248,249], crown ether [250,251], metallofullerene [252], tetraazacyclotetradecane [253], or Prussian blue type [254] in a conjugated organic material like PPy, PTh, or PANE Thick films are likely to be obtained provided that the polymer is redox active at the deposition potential due to this, Zotti et al. demonstrated that 5,5 -bis(3,4-(ethylenedioxy)thien-2-yl)-2,2 -bipyridine could be electropolymerized when complexed by iron and ruthenium, but not in the case of complexation by nickel or copper [71]. 

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