Thiocarbonate
Thiocarbonate describes a family of anions with the general chemical formula CS3−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. Thiocarbonates are salts of those ions as well (e.g. sodium dithiocarbonate Na2COS2). Thiocarbonates are esters of thiose ions as well. They contain trigonal planar divalent functional groups similar to these anions. (Wikipedia).
