CROWNED POLYACETYLENE .3. SYNTHESIS AND CATION-BINDING PROPERTY OF POLYPHENYLACETYLENE WITH AZACROWN CAVITY BY CYCLOPOLYMERIZATION OF ALPHA,OMEGA-BIS(4-ETHYNYLPHENOXY)OLIGOOXYETHYLENE CONTAINING A PYRIDYL UNIT

The cyclopolymerizations of 2,6-bis[7'-(4 ''-ethynylphenoxy)-2',5'-dio xaheptyl]pyridine (1a) and 2,6-bis[10'-(4 ''-ethynylphenoxy)-2',5',8'- trioxadecyl]pyridine (1b) were carried out using the (bicyclo[2.2.1]-h epta-2,5-diene)rhodium(I) chloride dimer. The yellowish powdery, organ ic solvent-soluble polymers were obtained using an amine as a cocataly st. The resulting polymers consisted of cyclic constitutional repeatin g units as the main structure along with pendant acetylenic groups, i. e. the extent of cyclization was from 0.89 to 0.99 for the polyphenyla cetylenes with an azacrown cavity, 2a and 2b, obtained from monomers l a and Ib, respectively. Polymer 2 exhibited cation-binding ability for alkaline earth metal, heavy metal, and transition metal ions and, in particular, for Ag+. The complex of 2 with Ag+, which was confirmed by the H-1 n.m.r. spectrum, consisted of the azacrown cavity and Ag+ wit h a ratio of 2. (C) 1997 Elsevier Science Ltd.