Thionyl fluoride, SOF 21 has been obtained as a fuming, gas by decomposing arsenic fluoride with thionyl chloride (Moissan and Lebeau, Corn pt.
Thionyl chloride, SOC1 21 may be obtained by the action of phosphorus pentachloride on sodium sulphite; by the action of sulphur trioxide on sulphur dichloride at 75 -80° C. (Journ.
On treatment with potassium bromide it yields thionyl bromide, SOBr2, an orange-yellow liquid which boils at 68° C. (40 mm.) (Hartoz and Sims, Chem.
In contact with chlorine monoxide it forms carbonyl chloride and thionyl chloride (P. Schiitzenberger, Ber., 1869, 2, p. 219).
Selenium tetrachloride, SeCl 4, is obtained by passing excess of chlorine over selenium; by the action of phosphorus pentachloride on selenium dioxide: Se0 2 +PC1 5 =SeOC1 2 +POC1 3 i 3SeOC12-I-2POC13=3SeC14-1-P205; and by the action of thionyl chloride on selenium oxychoride.