THE USE OF N-CHLOROSUCCINIMIDE FOR IDENTIFICATION OF BROMIDE AND IODIDE IONS
0
ROBERT FILLER Illinois Institute of Technology, Chicago 26
N-H~oAMI~ and E ~irnides are commonly used for halogenation of and halogen addition t o organic molec u l e ~ . ' ~These ~ compounds have also been employed as oxidizing a g e n k 3 Thus, benzyl alcohol is oxidized to benzaldehyde with N-chloros~ccinimide.~~~
A standard procedure for confirming the presence of bromide and iodide ions is their oxidation to bromine and iodine with "chlorine water." C1,
+ H,O = HOCl + H + + C1-
Hypochlorous acid is formed by this reaction t o only a slight extent (K = 4.7 X lo-'). It exists only in aqueous solution and is a powerful oxidizing agent. The reaction of N-chlorosuccinimide with water is an excellent source of HOC1: HIC-CO
I
HL-CO
+ H,O I \NC~
'
- d"" CHKO
CH2C Succinimide
VOLUME 35, NO. 8. AUGUST, 1958
+
During the past few years we have used this reagent as the oxidizing agent in preference t o "chlorine water." When this solid is dissolved in water, the resulting solution readiry oxidizes Br- and 1- to the respective halogen. The halogen is then concentrated by extraction with carbon tetrachloride or chloroform by following the conventional procedure for identification by color. The use of this reagent (containing 26.2% available chlorine) obviates the undesirable features of handling chlorine gas. We have found that 10 g. N-chlorosuccinimide dissolved in a liter of water gives a solution which is still useful after a month or more. It is generally necessary to heat the solution in order t o dissolve the solid completely. Since the reagent is available a t relatively reasonable cost,O the use of N-chlorosuccinimide is recommended for use in qualitative analysis courses. DJER~SSI, C., Cham. Revs., 43,271-317 (1948). E., J. Am. Cham. Soc., 71,1157 (1949). FIESER,L. F , AND 9. RAJAGOPALAN, J. Am. C h m . Sac., 71, 3935, 3938 (1949); 72, 5530 (1950). 4 HEBBELYNCK. M. F.. AND R. H. MARTIN, 5, . Ezpen'enlia, . 69 (1949). GROB,C. A,, AND H. V. SCAMID, Ezpe~ientia,5, 199 (1949). @Av;tilabI.blefrom Arapahoe Chemicals, Inc., and Eastman Kodak Co. (500 g./$9). ~ B U C K L E SR. ,
