Carbon subsulfide is an organic, sulfur-containing chemical compound with the formula and structure . This deep red liquid is immiscible with water but soluble in

organic solvent A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for ...

s. It readily polymerizes at room temperature to form a hard black solid.

Synthesis and structure

C₃S₂ was discovered by Béla Lengyel, who assigned it an unsymmetrical structure. Later,

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...

and Raman spectroscopy showed that the structure is symmetrical with a D_∞h

point group symmetry In group theory, the symmetry group of a geometric object is the group of all transformations under which the object is invariant, endowed with the group operation of composition. Such a transformation is an invertible mapping of the ambient ...

, i.e. S=C=C=C=S. This compound is analogous to

carbon suboxide Carbon suboxide, or tricarbon dioxide, is an organic, oxygen-containing chemical compound with formula and structure . Its four cumulative double bonds make it a cumulene. It is one of the stable members of the series of linear oxocarbons , w ...

whose structure is O=C=C=C=O. Lengyel first synthesized this compound by passing

carbon disulfide Carbon disulfide (also spelled as carbon disulphide) is a neurotoxic, colorless, volatile liquid with the formula and structure . The compound is used frequently as a building block in organic chemistry as well as an industrial and chemical n ...

(CS₂) vapor through an

electric arc An electric arc, or arc discharge, is an electrical breakdown of a gas that produces a prolonged electrical discharge. The current through a normally nonconductive medium such as air produces a plasma; the plasma may produce visible light. An ...

with carbon electrodes. This treatment produced a black solution that after filtration and evaporation gave a cherry-red liquid. He determined the molecular mass by

cryoscopy Freezing-point depression is a drop in the minimum temperature at which a substance freezes, caused when a smaller amount of another, non- volatile substance is added. Examples include adding salt into water (used in ice cream makers and for ...

. Later preparations of C₃S₂ include

thermolysis Thermal decomposition, or thermolysis, is a chemical decomposition caused by heat. The decomposition temperature of a substance is the temperature at which the substance chemically decomposes. The reaction is usually endothermic as heat is req ...

of a stream of CS₂ in a quartz tube heated to 900 to 1100 °C as well as flash vacuum

pyrolysis The pyrolysis (or devolatilization) process is the thermal decomposition of materials at elevated temperatures, often in an inert atmosphere. It involves a change of chemical composition. The word is coined from the Greek-derived elements ''py ...

(FVP) of 1,2-dithiole-3-thiones.

Reactions and occurrence

Among its few known reactions, C₃S₂ reacts with bromine to form the cyclic disulfide. C₃S₂ polymerizes under applied pressure to give a black semi-conducting solid. A similar pressure-induced polymerization of CS₂ also gives a black semiconducting polymer. In addition, reactions of C₃S₂ can yield highly condensed sulfur-containing compounds, e.g. the reaction of C₃S₂ with

2-aminopyridine 2-Aminopyridine is an organic compound with the formula H2NC5H4N. It is one of three isomeric aminopyridines. It is a colourless solid that is used in the production of the drugs piroxicam, sulfapyridine, tenoxicam, and tripelennamine. It is pr ...

. Using microwave spectroscopy, small C_nS₂ clusters have been detected in interstellar medium. The rotational transitions of these molecular carbon sulfides matched with the corresponding molecules.

References

{{Carbon compounds Organic compounds Foul-smelling chemicals