Carbon+disulfide

Carbon disulfide is
a colorless volatile liquid with the formula CS2. The compound is used frequently as a building block in organic chemistry as well as an industrial and chemical non-polar solvent. It has an "ether-like" odor, but commercial samples are typically contaminated with foul-smelling impurities, such as carbonyl sulfide

Occurrence and manufacture
Small amounts of carbon disulfide are released by volcanic eruptions and marshes. CS2 once was manufactured by combining carbon (or coke) and sulfur at high temperatures. A lower temperature reaction, requiring only 600 °C utilizes natural gas as the carbon source in the presence of silica gel or alumina catalysts:

2CH4 + S8 → 2CS2 + 4H2S

The reaction is analogous to the combustion of methane. Although it is isoelectronic with carbon dioxide, CS2 is highly flammable:

CS2 + 3O2 → CO2 + 2SO2

Reactions
Compared to CO2, CS2 is more reactive toward nucleophiles and more easily reduced. These differences in reactivity can be attributed to the weaker π donor-ability of the sulfido centers, which renders the carbon more electrophilic. It is widely used in the synthesis of organosulfur compounds such as metham sodium, a soil fumigant and is commonly used in the production of the soft fabric viscose.

Addition of nucleophiles
Nucleophiles such as amines afford dithiocarbamates:

2R2NH + CS2 → [R2NH2+][R2NCS2−]

Xanthates form similarly from alkoxides:

RONa + CS2 → [Na+][ROCS2−]

This reaction is the basis of the manufacture of regenerated cellulose, the main ingredient of viscose, rayon and cellophane. Both xanthates and the related thioxanthates (derived from treatment of CS2 with sodium thiolates) are used as flotation agents in mineral processing.

Sodium sulfide affords trithiocarbonate:

Na2S + CS2 → [Na+]2[CS32−]

Chlorination
Chlorination of CS2 is the principal route to carbon tetrachloride: CS2 + 3[|Cl2] → CCl4 + [|S2Cl2]

This conversion proceeds via the intermediacy of thiophosgene, CSCl2.

Coordination chemistry
CS2 is a ligand for many metal complexes, forming pi complexes. One example is CpCo([|η2]-CS2)(PMe3).[|[][|2][|]]