Poly(p-phenylenediethynylene phosphane): A Phosphorus-Containing Macromolecule that Displays Blue Fluorescence Upon Oxidation

摘要

Despite the challenges associated with their synthesis, hybrid inorganic-organic polymers featuring heavier main-group elements spaced by pi-conjugated organic functionalities have garnered considerable recent attention due to their chemical functionality and novel photophysical properties. We have succeeded in the preparation of an unprecedented organophosphorus polymer possessing functional phosphane-di-yne moieties in the main chain. Namely, poly(p-phenylenediethynylene phosphane) (PPYP) is prepared using a nickel(II)-catalyzed P-C bond-forming reaction. The hexyl-substituted PPYPs are solution processible and have been thoroughly characterized (molecular weight, M-w, ca. 10(4) Da vs. polystyrene; degree of polymerization, DP, ca. 10). Remarkably, although PPYP shows very weak emission upon irradiation with UV light, its oxide shows blue "turn-on" fluorescence. The present discovery bridges the areas of main-group and polymer science and opens the door to a new class of sigma-pi-conjugated macromolecules with unique chemical functionality.