Polyelectrolytes of Inorganic Polyoxometalates: Acids, Salts, and Complexes

Lu, ZQ (Lu, Zhuo-Qun) 1Zhang, LL (Zhang, Lan-Lan) 1Yan, YK (Yan, Yukun) 2Wang, W (Wang, Wei) 1

MACROMOLECULES, 2021, 54(14): 6891-6900

DOI 10.1021/acs.macromol.1c00783

Abstract

Hybrid polyelectrolytes comprising a polynorbornene backbone and pendant polyoxometalate (POM) groups, with different degrees of polymerization (DP = 100, 200, and 400), are described. The tetrabutylammonium counterions associated with the POM [(P2V3W15O62)(9-); molecular weight = 3964 Da] groups were exchanged for protons and alkali-metal cations by two cation-exchange methods, without breaking the covalent bond between the POM cluster and the polymer chain. The structural integrity of the POM clusters, which is maintained in anionic polyelectrolytes with ionization numbers ranging from 1.1-4.8 to above six, enables their combination with chiral organic cations to induce chiroptical activity in POMs and with polycations to form polyelectrolyte complexes. We compared the ionization behavior of POM polyelectrolytes with those of POM hybrids and inorganic POM clusters. POM polyelectrolytes have promising applications in electrochemistry, catalysis, and materials science, as well as in electrochromic and photochromic devices.