(II) in which n and m are the same or different and are whole numbers from 1 to 6, the R groups are the same or different and have the meaning attributed to R in subparagraph (a) of this claim, and in which A is selected from the group consisting of --NH-- and --NH--(CH2 --CH2 --NH)n -- in which n is a whole number from 1 to 6; (d) a compound of the for