2096. Chlorine Dioxide

Nomenclature

CAS number: 10049-04-4
Chlorine peroxide.
ClO2; mol wt 67.45.
Cl 52.56%, O 47.44%.

Description and references

Prepn from chlorine and sodium chlorite: Derby, Hutchinson, Inorg. Synth. 4, 152 (1953); from potassium chlorate and sulfuric acid: Bodenstein et al., Z. Anorg. Allg. Chem. 147, 233 (1925); by passing NO2 through a column of sodium chlorate: Hutchinson, Derby, Cereal Chem. 24, 372 (1947); alternate methods of prepn: Schmiesser in Handbook of Preparative Inorganic Chemistry vol. 1, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1963) p 301. Review: Bedumeau, Rev. Prod. Chim. 57, 173-177, 257-261 (1954). Book: W. J. Masschelein, Chlorine Dioxide, R. G. Rice, Ed (Ann Arbor Science Publishers Inc., Ann Arbor, MI, 1979) 189 pp. Review of toxicology and human exposure: Toxicological Profile for Chlorine Dioxide and Chlorite (PB2003-101465, 2002) 182 pp.

Properties

Strongly oxidizing, yellow to reddish-yellow gas at room temp. Unpleasant odor similar to that of chlorine and reminiscent of that of nitric acid. Unstable in light; stable in dark if pure, but chlorides catalyze its decompn even in the dark. Oxidizer, poisonous. Reacts violently with organic materials. In concns in excess of 10% at atm pressure easily detonated by sunlight, heat, contact with mercury or carbon monoxide. mp -59°; bp 11°; d0(liq) 1.642: Cheesman, J. Chem. Soc. 1930, 35. Sol in water (3.01 g/l at 25° and 34.5 mm Hg), with slight hydrolysis to chlorous and chloric acid; sol in alkaline and sulfuric acid solns. Solid is yellowish-red crystalline mass; liquid is reddish-brown.

Caution

Potential symptoms of overexposure are irritation of eyes, nose and throat; coughing, wheezing, bronchitis, pulmonary edema; chronic bronchitis. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 58.

Use

Bleaching cellulose, paper-pulp, flour, leather, fats and oils, textiles, beeswax; purification of water; taste and odor control of water; cleaning and detanning leather; manuf of chlorite salts; oxidizing agent; bactericide, antiseptic and deodorizer.