First prepd from cobalt trifluoride and elemental sulfur: Fischer, Jaenckner, Angew. Chem. 42, 810 (1929); Kwasnik in Handbook of Preparative Inorganic Chemistry vol. 1, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1963) pp 168-169. Best prepared from SCl2 and NaF suspended in acetonitrile; also from sulfur, chlorine and sodium fluoride: Tullock et al., J. Am. Chem. Soc. 82, 539 (1960); Arth, Fried, US 3046094 (1962 to Merck & Co.); Fawcett, Tullock, Inorg. Synth. 7, 119 (1963). Reviews of prepn and chemistry: Smith, Angew. Chem. Int. Ed. 1, 467-475 (1962); Kemmitt, Sharp, Adv. Fluorine Chem. 4, 220-222 (1965); Martin, Ann. N.Y. Acad. Sci. 145, 161-168 (1967).