4799. Hydrogen Selenide

Nomenclature

CAS number: 7783-07-5
Selenium hydride.
H2Se; mol wt 80.98.
H 2.49%, Se 97.51%.

Description and references

Prepd by heating selenium and hydrogen in a sealed tube at 440°: Hautefeuille, Bull. Soc. Chim. [2] 7, 198 (1867); by passing a mixture of hydrogen and selenium vapor over pumice stone at 440°: Corenwinder, Ann. Chim. Phys. [3] 34, 77 (1852); by warming potassium or ferrous selenide with hydrochloric acid: Berzelius, Acad. Handl. Stockholm 39, 13 (1818); by the action of water on aluminum selenide: Fonzes-Diacon, Traité de Chimie Minérale, Paris 1, 469 (1904); Waitkins, Shutt, Inorg. Synth. 2, 183 (1946). Review of chemistry and toxicity: Medical and Biologic Effects of Environmental Pollutants: Selenium (Nat. Acad. Sci., Washington D.C., 1976) 203 p.

Properties

Gas. Disagreeable odor. Highly toxic and reactive gas that decomposes rapidly in presence of oxygen to form elemental Se and H2O. d442 2.12. bp 41.3°. Liquefies at 0° under a pressure of 6.6 atm; at 18°, 8.6 atm; at 52°, 21.5 atm; at 100°, 47.1 atm; at the crit temp 137°, 91.0 atm. mp 65.73°. v.p. at 30°, 1.75 atm; v.p. at 0.2°, 4.5 atm; v.p. at 30.8°, 12 atm. K1 at 25° = 1.30×104; K2 at 25° = 1×1011. Poisonous, flammable. Soly in water (ml/100 ml): 377 (4°); 270 (22.5°). Sol in carbonyl chloride and carbon disulfide. Unites directly with most metals to form metal selenides.

Caution

Potential symptoms of overexposure are irritation of eyes, nose and throat; nausea, vomiting and diarrhea; metallic taste, garlic breath; dizziness, lassitude and fatigue; direct contact with liquid may cause frostbite. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 168.