主权项 |
1. A phosphonamide oligomer comprising a compound of Formula II: wherein each of R1, R2, R3, R4, and R5 is individually a C1 to C20 alkyl or, optionally substituted, aryl group; each of X1, X2, X3, and X4 is individually, an aromatic, cycloalkyl, or aliphatic group; n and m are an integer of from 0 to about 20; and each Z is, independently: |