Carbon subsulfide
Chemical compound
From Wikipedia, the free encyclopedia
Carbon subsulfide is an organic, sulfur-containing chemical compound with the formula C3S2 and structure S=C=C=C=S. This deep red liquid is immiscible with water but soluble in organic solvents. It readily polymerizes at room temperature to form a hard black solid.
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| Names | |
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| Preferred IUPAC name
Propa-1,2-diene-1,3-dithione | |
| Other names
Carbon Subsulfide, Tricarbon Disulfide | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
PubChem CID |
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CompTox Dashboard (EPA) |
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| Properties[1] | |
| C3S2 | |
| Molar mass | 100.15 g·mol−1 |
| Appearance | bright red liquid |
| Odor | stifling |
| Density | 1.319 g·cm−3[2] |
| Melting point | −0.5 °C (31.1 °F; 272.6 K) |
| Boiling point | Decomposes at 90 °C (194 °F; 363 K) |
| insoluble | |
| Related compounds | |
Related compounds |
Carbon suboxide Carbon disulfide Ethenedithione |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis and structure
C3S2 was discovered by Béla Lengyel,[3] who assigned it an unsymmetrical structure. Later, infrared and Raman spectroscopy showed that the structure is symmetrical with a D∞h point group symmetry,[4] i.e. S=C=C=C=S. This compound is analogous to carbon suboxide whose structure is O=C=C=C=O.
Lengyel first synthesized this compound by passing carbon disulfide (CS2) vapor through an electric arc 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. Later preparations of C3S2 include thermolysis of a stream of CS2 in a quartz tube heated to 900 to 1100 °C as well as flash vacuum pyrolysis (FVP) of 1,2-dithiole-3-thiones.[5]
Reactions and occurrence
Among its few known reactions, C3S2 reacts with bromine to form the cyclic disulfide.[6]
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.
Using microwave spectroscopy, small CnS2 clusters have been detected in interstellar medium.[7] The rotational transitions of these molecular carbon sulfides matched with the corresponding molecules.