Polymer and Materials Science
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
The modification of polystyrenes (1 - 8% cross-linked) by imidazole ligands, via chloromethylation, is described. The resulting resins, having 10-40% of the phenyl groups substituted by a —CH2—(N)-imidazolyl group, have been treated with first-row transition metal salts under varying conditions. Upon reaction of the modified polymer with the transition metal salts in CHCl3, a shrinking of the polymer is observed which is explained by additional cross-linking by the metal ions. The final products have the general formula Mt(PS-Iz)m (NnBuIz)nX2, in which PS-Iz stands for a polystyrene-bound imidazole ligand, NnBuIz for N-butylimidazole (a ligand used to solubilize the metal salts in CHCl3) and X for the anion (perchlorate, nitrate, tetrafluoroborate, chloride, bromide). Metal ions used are Co(II), Ni(II), Cu(II), and Zn(II); values of 2-6 have been found for m in most cases. The value of n usually is very small (0,2-1,0) in most cases. Spectroscopically the polymeric coordination compounds behave like the corresponding monomeric coordination compounds, Mt(N-benzylimidazole)mX2, indicating that the imidazole ligands in the polymer are quite flexible in their coordination behaviour, except in case of very low degrees of substitution or high degrees of cross-linking.
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