Title: Chlorine Heptoxide
CAS Registry Number: 10294-48-1
Additional Names: Dichlorine heptoxide; perchloric anhydride
Molecular Formula: Cl2O7
Molecular Weight: 182.90
Percent Composition: Cl 38.77%, O 61.23%
Literature References: Prepd by dehydration of perchloric acid with P2O5: Michael, Conn, Am. Chem. J. 23, 445 (1900); 25, 92 (1901); Meyer, Kessler, Ber. 54, 566 (1921); Goodeve, Powney, J. Chem. Soc. 1932, 2078.
Properties: Colorless, very volatile oily liquid. d40 1.86. mp -91.5°; bp 82°; bp23.7 0°. Trouton constant 23.4. The most stable oxide of chlorine. Explodes violently upon concussion or on contact with a flame or iodine. Dipole moment in CCl4 at 20° is 0.72. Does not attack wood or paper. Slowly hydrolyzed by water, forming perchloric acid.
Melting point: mp -91.5°
Boiling point: bp 82°; bp23.7 0°
Density: d40 1.86
CAUTION: May be irritating to skin, mucous membranes.
Use: Catalyst in cellulose esterification.