A composition has a structure as shown in formula I: R1 and R2 are independently at each occurrence an aliphatic radical having from 1 to about 10 carbons, a cycloaliphatic radical having from about 3 to about 10 carbons, or an aromatic radical having from about 3 to about 12 carbons; R3, R4, and R5 are independently at each occurrence a hydrogen atom, an aliphatic radical having from 1 to about 10 carbons, a cycloaliphatic radical having from about 3 to about 10 carbons, or an aromatic radical having from about 3 to about 12 carbons; R6 and R7 are independently at each occurrence a hydrogen atom or an aliphatic radical having from 1 to about 6 carbons; X is a halogen; and “n” is an integer having a value of from 0 to about 4.