Preparation of Poly(silylene-p-phenylene)s Bearing a Benzo Crown Pendant Group and Their Iono- and Solvatochromic Behavior in the Emission Spectra

Poly(silylene-p-phenylene)s bearing a benzo crown pendant group were obtained as colorless solids in moderate yield by the reactions of poly[chloromethyl- or ethoxymethylsilylene-p-phenylene] with lithiated benzo crown ethers in THF. The benzo crown substituted polymers responded to selected alkali-metal or alkaline-earth-metal ions in the emission spectra, depending on the crown ether ring size. Thus, when appropriate metal ions were added to the polymer solutions, the intensity of a maximum broad emission band around 400 nm decreased and a band at about 320 nm was markedly enhanced. Similar chromism of the polymers was also observed, depending on the solvent polarity in the absence of metal ions.