Feb. 18,2021  34  US 2021/0048748 Al  -continued  -continued  [0087]  Examples of the anion in the monomer from which  recurring unit  (f)  is derived are shown below, but not limited  thereto.  RA  is as defined above.  XR’  0  0  F2  0  C  ’-...../ ’-s03- 0  F  S03- RA  F3C  S03- XR’  0  0  ’:¢  I#  F  S03- F  F  F  F  F  F  F  F  S03- S03- RA  XR"  0  0  F3C  s>  S03- F  S03- XR’  0  0  XR’  0  0  F  F  F  I  #  F  S03- S03-