Chem. [f. TRI- 5 + THIO-.] Prefix denoting that three atoms of sulphur have been substituted for three atoms of oxygen in the substance designated by the rest of the name; e.g., trithiocarbonic acid, H2CS3, derived from carbonic acid, H2CO2; trithiocarbonate, a salt of this acid. In many cases, however, tri- refers to the whole substance and not to the sulphur alone; e.g., trithio-acetaldehyde, (CH3CHS)3, a compound of three molecules of thio-acetaldehyde, CH3CHS.
1894. Muir & Morley, Watts’ Dict. Chem., IV. 692. Tri-Thio-Citric Ether C3H5O (CO . SEt)3 … Oil, smelling like mercaptan.
1899. Smith, Richter’s Org. Chem. (ed. 3), I. 203. Trithio-formaldehyde (CH2S)3, melts at 216°.
1910. Walker & Mott, Holleman’s Org. Chem. (ed. 3), 348. Carbon disulphide … With alkali-metal or alkaline-earth-metal sulphides it yields trithiocarbonates.
