POLYMERIC PSEUDOCROWN ETHERS .1. SYNTHESIS AND COMPLEXATION WITH TRANSITION-METAL ANIONS

Polymeric pseudocrown ethers (PPCE) are prepared by the reaction between chloromethylated styrene-divinylben-zene copolymers and polyoxyalkylene under Williamson ether-synthesis conditions. Synthetic aspects, the polymer selection, and reaction conditions are discussed. Effective PPCE synthesis is obtained with flexible polymers, and high cyclization yields are obtained, even when 3 molar excess of the diol is used. A detailed study of the coordination of transition metals, including Au3+, Fe3+, and Zn2+, as chlorides, bromides, or iodides in HX and/or NaX solutions show that PPCE coordinate MX4-or MX42-complexes (M = Au, Fe, Zn; X = CI, Br, 1) without competition from large excess of hydrogen or X ions. The coordination patterns of the various PPCE show that coordination is most effective when the anions fit well in the PPCE cavity (whose dimensions were estimated from Corey-Pauling-Koltun models). The coordination of MX4-or MX42-anions (ionic diameter 9-11 Å) is most effective with PPCE-14 (incorporating 14 oxygens, cavity diameter 10.5-13 Å) and falls off to zero with PPCE-4 (incorporating four oxygens). © 1979, American Chemical Society. All rights reserved.