ABSTRACT
This chapter describes unique redox and stereochemistry of salen complexes, which are of fundamental importance for excellent functionalities. Another important advantage is that metal complexes having various electronic and stereochemical properties are created simply changing salicylaldehydes and diamines. Salen complexes have electron-rich phenolates, which could be reversibly converted to phenoxyl radicals under oxidizing conditions. The redox cycle between phenolate and phenoxyl radical can function as an additional redox site beside the metal ion. Redoxnoninnocence of salen ligands is quite an important property one should keep in mind in using salen complexes. An important lesson from the present experimental studies is that the structure of salen ligands alone may not be enough to determine the stereochemistry of salen complexes. Excellent catalytic activity of manganese and cobalt salen complexes prompted to investigate their electronic and stereochemicalproperties. One of new findings is that the conformation of salencomplexes is altered by unexpected two factors.
