Anion-solvating polymer membranes

A compound comprising a structure of formula (I):

• or a salt thereof,
• wherein:
• each Ar comprises, independently, an optionally substituted aromatic or optionally substituted arylene;
• each Y1 is, independently, EW and each Y2 is, independently, Ak;
• or Y1 and Y2, taken together, comprises an optionally substituted heterocyclic amino;
• each Z is, independently, selected from the group consisting of —O—, —S—, —NRN1— —NRN1RN2—, and —CRC2RC3—, in which each of RN1, RN2, RC2, and RC3 is, independently, H, optionally substituted alkyl, or optionally substituted aryl, and in which at least one Z is not —CRC2RC3— or in which at least one Z is not —N(CH3)2—;
• each Ak is, independently, optionally substituted alkylene;
• x is 1 to 20;
• each FG is, independently, selected from the group consisting of optionally substituted alkyl, optionally substituted aryl, hydroxy, amino, ammonium cation, sulfo, sulfonate anion, phosphono, phosphonate anion, carboxyl, carboxylate anion, heterocyclic cation, or a salt form thereof;
• each EW is, independently, selected from the group consisting of haloalkyl, optionally substituted heteroaryl, amino, amido, nitrile, and —C(═O)RC1, in which RC1 is H, hydroxy, alkoxy, alkyl, or oxygen anion (O−);
• each Ra is, independently, H, optionally substituted alkyl, optionally substituted aryl, or optionally substituted heteroaryl;
• and
• each of m and n is, independently, 1 to 1,000,000.