Thioxoethenylidene, is a reactive heteroallene molecule with formula CCS.[1]
CCS is found in space in large quantities.[1] This includes the Taurus Molecular Cloud in TMC-1, TMC-1c and L1521B. These are likely in young starless molecular cloud cores.[2]
By condensing propadienedithione SCCCS or thioxopropadienone OCCCS in solid argon and irradiating with ultraviolet radiation, CCS is formed.[1] Another way is via a glow discharge in a mixture of carbon disulfide and helium. Yet another way is through electron irradiation of sulfur containing heterocycles.[1]
CCS and the anion CCS− can be formed in solid neon matrices also.[3]
CCS can be a ligand. It can form an asymmetrical bridge between two molybdenum atoms in Mo2(μ,σ(C):η2(C′S)-CCS)(CO)4(hydrotris(3,5-dimethylpyrazol-1-yl)borate)2 In this one carbon atom has a triple bond to a molybdenum and the other has a double bond to the other molybdenum atom, which also has a single bond to the sulfur atom.[4]
The ultraviolet spectrum shows absorption bands between 2800 and 3370 Å and also in the near infrared between 7500 and 10000 Å.[1] CCS can react with CCCS to form C5S.[1]
The infrared spectrum in solid argon shows a vibration band at 1666.6 cm−1 called v1 and another called v2 at 862.7 cm−1. The 2v1 overtone is at 3311.1 cm−1. A combination vibration and bending band is at 2763.4 cm−1[1]
The microwave spectrum has emission lines 43 − 32 at 45.4 GHz and 21 - 10 at 22.3 GHz, important for detection of molecules in molecular clouds.[2]
Theoretical predictions show that the C-C bond is 1.304 Å long and the C–S bond is 1.550 Å.[5]