Thiocarbonate

Thiocarbonate describes a family of anions with the general chemical formula CS
3−xO2−
x (x = 0, 1, or 2):

  • for x = 2 it is monothiocarbonate ion CO2S2−
  • for x = 1 it is dithiocarbonate ion COS2−2
  • for x = 0 it is trithiocarbonate ion CS2−3

Like the carbonate dianion, the thiocarbonate ions are trigonal planar, with carbon atom at the center of triangle, and oxygen and sulfur atoms at the peaks of the triangle. The average bond order between C and S or O is ⁠4/3⁠. The state of protonation is usually not specified. These anions are good nucleophiles and good ligands.[1][2]

Thiocarbonates refer to salts of those ions as well (e.g. potassium trithiocarbonate, K2CS3).

Thiocarbonates refer to esters of those ions as well (e.g. dimethyl trithiocarbonate, (CH3S)2CS). They contain trigonal planar divalent functional groups R–CS
3−xO
x–R similar to these anions (x = 0, 1, or 2, R is organyl group). Esters with the formula R−O−C(=S)−S−R are also called xanthates, while esters with the formula R−S−C(=S)−S−R are also called thioxanthates.

Thiocarbonates also refer to salts of organyl thiocarbonate ions (e.g. sodium ethyl xanthate or SEX, CH3CH2OCS−2Na+). They contain R–CS
3−xO−
x anions (x = 0, 1, or 2, R is organyl group). Anions with the formula R−O−CS−2, and their salts, are also called xanthates, while salts with the formula R−S−CS−2, and their salts, are also called thioxanthates.

  1. ^ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5
  2. ^ Gattow, Gerhard; Behrendt, Werner (1977). Carbon Sulfides and their Inorganic and Complex Chemistry. Stuttgart: Georg Thieme. ISBN 3-13-526201-4.