Schiff base oligomers

An oligomer represented by Formula (IV):

• wherein:
• each instance of R9 is independently selected from the group consisting of alkyl, cycloalkyl, aryl, heteroaryl, and ether;
• each instance of R28 and R29 is independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, and aryl;
• each instance of R33 is independently selected from the group consisting of alkyl, cycloalkyl, aryl, heterocyclyl, and a bond;
• each instance of R41 is independently —NH— or a bond and each instance of R40 is independently —NH— or —NH—NH—;
• each instance of R42 is independently —NH— or a bond and each instance of R43 is independently —NH— or —NH—NH—;
• each instance of z and t is an integer of 1 to 50;
• R44 is hydroxyl or decarboxylated derivative thereof, or is represented by the structure:
• wherein:
• R1 is hydrogen or silyl;
• R2 and R3 are independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, and aryl;
• R31 is selected from the group consisting of alkyl, cycloalkyl, aryl, heterocyclyl, and a bond;
• R50 is —NH— or a bond and R32 is —NH— or —NH—NH—;
• R34 is —NH— or a bond and R35 is —NH— or —NH—NH—;
• and
• x is an integer of 1 to 50;
• and
• R30 is hydrogen, silyl, or is represented by the structure:
• where:
• R9′ selected from the group consisting of alkyl, cycloalkyl, aryl, heteroaryl, and ether;
• and
• R44′ is hydroxyl or decarboxylated derivative thereof.