| abstract |
A novel chelating agent having the formula <IMAGE> +TR in which (a) each of X1, X2, X3, and X4 is a member selected from the group consisting of (i) hydrogen; (ii) an alkyl group having 1-4 carbon atoms; (iii) -CN; (iv) -SO3M1; (v) -COOM1; (vi) -OM3; (vii) -NO2; (viii) -OH; and <IMAGE> (ix) in which each of R1 and R2 is an alkyl group having 1-4 carbon atoms; (b) each of M1, M2, M3, and M4 is a member selected from the group consisting of (i) a hydrogen ion; (ii) an alkali metal ion; (iii) 1/2 an alkaline earth metal ion; and (vi) an ammonium ion having the formula <IMAGE> in which each of R3, R4, R5, and R6 is a member selected from the group consisting of (A) hydrogen; (B) an alkyl group having 1-4 carbon atoms; and (C) a hydroxyalkyl group having 1-4 carbon atoms; and (c) Z is a member selected from the group consisting of (i) hydrogen; and (ii) hydroxyl. |