Nomenclature
CAS number: 75-11-6
Diiodomethane.
CH
2I
2; mol wt 267.84.
C 4.48%, H 0.75%, I 94.76%.
Description and references
Prepd by the reduction of iodoform with sodium
arsenite: Adams, Marvel, Org. Synth. vol. 1, p 57 (1921). Also by heating iodoform with sodium
acetate in alcohol: Bagnara, Eng. Min. J.
Press 116, 51 (1923). Absorption spectrum:
Lowry, Sass, J. Chem. Soc. 1926, 624; Stepanov, Acta Physicochim.
URSS 20, 174 (1945).
Properties
Very heavy, highly refractive liq. Darkens on
exposure to light, air, and moisture. d420 3.32537. Solidifies
in leaflets at 5.2° or in thin needles at 5.7°. Usually cooling to
0° is necessary to start crystn. mp 6.0°. bp760 181°; bp70 107°; bp11 68°. nD10.5 1.7559; nD15 1.7425. Viscosity (cP): 3.35 (10°); 2.80 (20°); 2.39 (30°). Sol
in about 70 parts water; miscible with alcohol, propanol, isopropanol,
hexane, cyclohexane, ether, chloroform, benzene. CH2I2 dissolves sulfur and phosphorus (more than 1:1 at 25°).Use
In separating mixtures of minerals. In determining
the specific gravity of minerals and other substances. In the manufacture
of x-ray contrast media.