Synthetic Polymeric Ligands

Apart from a simple addition of a Crm salt to a polymeric ligand, several synthetic methods for specific complexes have been developed. For example, S2-linked tris-(/3-diketonato) complexes (215) (Scheme 29a) have been synthesized by a reaction of a preformed Cr111 complex with S2CI2.1 21 Similarly, preformed Cr111 complexes with porphyrin or salen ligands have been... 

Several books are devoted to the chiral separations in HPLC [69,93,104,108,110]. Among several hundreds of CSPs described, ligand-exchange [105], Pirkle-type [113], protein and peptide [114], polysaccharide [115], macrocyclic [93,116], and synthetic polymeric [117-119] CSPs are most widely used. 

The homogeneous type macromolecule-metal complex is synthesized by the reaction of synthetic or natural polymers containing donating groups, such as hydroxyl, carboxylic acid, ketone, phosphoric acid, amine, heterocyclic nitrogen, or thiol, with metal ions. The typical polymeric ligands are... 

Tertiary stibines have been widely employed as ligands in a variety of transition metal complexes (99), and they appear to have numerous uses in synthetic organic chemistry (66), eg, for the olefination of carbonyl compounds (100). They have also been used for the formation of semiconductors by the metal—organic chemical vapor deposition process (101), as catalysts or cocatalysts for a number of polymerization reactions (102), as ingredients of light-sensitive substances (103), and for many other industrial purposes. 

One method of solving the kinetics dilemma is well known in coordination chemistry that is, start with a labile metal ion and render it inert during the course of the synthetic reaction. We have accomplished this in the case of zirconium(IV) by starting with tetrakis(salicylaldehydo)zirconium(IV), which is quite labile, and polymerization with 1,2,4,5-tetraaminobenzene in a Schiff-base condensation reaction in situ (6). The polymeric product contains a "double-headed" quadridentate ligand, which is much more inert to substitution. However, 1,2,4,5-tetraaminobenzene has become very expensive. Therefore, the synthesis of a zirconium polymer with 3,3, 4,4 -tetraaminobiphenyl (commercially 3,3 -diami nobenzidine) with zirconium salicylaldehyde, Zr(sal)4 (7) has been undertaken as shown below ... 

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