Nomenclature
CAS number: 12279-90-2
2,4,6,8-Tetrathia-1,3,5,7-tetraarsatricyclo[3.3.0.0
3,7]octane; red arsenic sulfide; realgar; red orpiment; ruby arsenic; red arsenic glass; tetraarsenic tetrasulfide; C.I. Pigment Yellow 39; C.I. 77085.
As
4S
4; mol wt 427.95.
As 70.03%, S 29.97%.
Description and references
Prepn: Gmelins, Arsenic (8th ed.) 17, pp 417-422 (1952); Schenk in Handbook of Preparative Inorganic Chemistry vol 1, G. Brauer, Ed. (Academic Press, New York, 2nd
ed., 1963) p 603.
Properties
Deep red, lustrous monoclinic crystals. mp 320°; bp 565°; d 3.5. Ignites at high temp. Practically insol
in water; sol in alkali hydroxides; decomposed by HNO3;
very slightly sol in hot CS2 and benzene.Use
As pigment in painting; in fireworks as blue fire
and to give an intense white flame; manuf shot; calico printing and
dyeing; tanning and depilating hides.