Bulk polymerised metal-coordinating polymeric receptors

Bulk polymerised metal-coordinating polymeric receptors 

Metal-ion coordination in designing molecularly imprinted polymeric receptors 

Using Co as the metal centre, 1-vinyl imidazole as the functional monomer and amino acids as the templates, Leonhardt and Mosbach prepared imprinted metal-complexing polymers [14]. These polymers were aimed at being used as enzyme-like substrate specific catalysts (for more details, see Section 6.5.3.). 

The paramagnetic nature of Cu ion was utilised to characterise these polymeric receptors by studying the interaction between the Cu centres and imidazole groups using ESR spectroscopy [17]. Results from the ESR experiments indicate that Cu -imidazole coordination bonds formed during the assembly of the monomer and template are conserved upon polymerisation. Furthermore, analysis of the ESR data obtained for different polymers suggested a defined arrangement of metal ion sites in the templated materials, which is absent in the non-templated control polymers. 

In competitive substrate binding experiments, the polymers showed selectivity for the templates with which they were made. On the other hand, non-templated control polymers showed statistical preference for both substrates. Some results on the substrate selectivities of these polymers are presented in Table 6.1. It is particularly notable from this study that these imprinted polymers could distinguish positional isomers (4 and 5), which differ in their imidazole spacing by only 4 A. 

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Bulk polymerised metal-coordinating polymeric receptors... 

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