Chelation bound polymers

Porous polymers containing various metal chelates bound to nitrogen functionalities have been used to separate oxygen from argon, nitrogen, and carbon monoxide [25]. The porous polymer is synthesized with pyridyl functional groups, which serve as an axial base for the metal chelate in coordinate bond formation between the metal chelate and the polymer. It also serves to activate the metal complex for oxygen coordination. 

As reaction proceeds, the polymer chain (which is in random coil form) unwinds as the charge on it grows as a result of neutralization and ionization. This contributes to thickening of the cement paste. Cations released become bound to the polymer chain. Countercations can either be bound to a polyanionic chain by general electrostatic forces or be site-bound at specific centres. More than one type of site binding is possible. Complex formation and, if the ligand is bidentate, chelate formation enhance the effect. 

Polymer bound Schiff s bases are receiving increasing attention, as these materials are expected to combine the selective properties of low molecular weight Schiff s base chelates with the advantage of polymer immobilization. Wohrle et al. [7] synthesized a copolymer of 2-butylimino-4-vinylphenol with S to prepare O-chelates [7]. 

The [Ru(bpy)3]2+ photosensitized reduction of methyl viologen (MV2+) proceeds rapidly in water-swollen iminodiacetic acid type chelate resin beads which adsorb both [Ru(bpy)3]2+ and MV2+ (RM resin). The reduction takes place with the aid of polymer-bound iminodiacetate as a donor 102). Photosensitized formation of hydrogen peroxide occurs in an aqueous solution containing RM resin and oxygen molecules (Fig. 8)102 The some reaction also occurs using a polystyrene-coated filter paper, onto which both [Ru(bpy)3]2 + and MV2+ were adsorbed 103). 

In conclusion, the incorporation of Gd(III) complexes into macromolecular systems (dendrimers, linear polymers, micelles) does not significantly affect the water exchange kinetics, exceptions have only been found for few protein bound chelates. 

Fig. 11 Uptake and release of templates by the imprinted polymer. On the left the free cavity is shown. On the right, the template is bound by two chelated hydrogen bridges including an ion pair...

In all cases, some of the V was released into solution this amount can be decreased by cosupporting Cu on the catalyst (50). Kumar et al. (51) used a polymer-bound Schiff base to chelate V02+ the resulting polymer was active for benzene hydroxylation with H2O2 ... 

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