ethenedithione
{{technical|date=June 2023}}
{{Chembox
|ImageFile=Ethenedithione.png
|IUPACName=Ethenedithione
|Section1={{Chembox Identifiers
|CASNo = 83917-77-5
|ChemSpiderID = 26668537
|DTXSID = DTXSID20834263
|PubChem = 71414826
|StdInChI=1S/C2S2/c3-1-2-4
|StdInChIKey = JFSYYGOHKMDXOA-UHFFFAOYSA-N
|SMILES = C(=C=S)=S
}}
|Section2={{Chembox Properties
|C=2|S=2
}}
}}
Ethenedithione or ethylenedithone is an unstable chemical substance with formula S=C=C=S made from carbon and sulfur.
Ethenedithione can exist as a gas at low pressure and high temperature, but is unstable when condensed or under higher pressure.{{cite journal |last1=Wentrup |first1=Curt |last2=Kambouris |first2=Peter |last3=Evans |first3=Richard A. |last4=Owen |first4=David |last5=Macfarlane |first5=Graham |last6=Chuche |first6=Josselin |last7=Pommelet |first7=Jean Claude |last8=Cheikh |first8=Abdelhamid Ben |last9=Plisnier |first9=Michel |last10=Flammang |first10=Robert |title=2,5-Dithiacyclopentylideneketene and ethenedithione, S:C:C:S, generated by flash vacuum pyrolysis |journal=Journal of the American Chemical Society |date=April 1991 |volume=113 |issue=8 |pages=3130–3135 |doi=10.1021/ja00008a048}}
It can be stabilized as a ligand binding two cobalt atoms.{{cite journal |last1=Seidel |first1=Wolfram W. |last2=Meel |first2=Matthias J. |last3=Hughes |first3=Stephen R. |last4=Hupka |first4=Florian |last5=Villinger |first5=Alexander |title=Ethenedithione (S=C=C=S): Trapping and Isomerization in a Cobalt Complex |journal=Angewandte Chemie International Edition |date=23 December 2011 |volume=50 |issue=52 |pages=12617–12620 |doi=10.1002/anie.201105055}}
Other occurrences as a ligand are in TpW(CO)2(C2S2)– and [TpW(CO)2]2Ni(C2S2)2, where Tp is trispyrazolylborate.{{cite journal |last1=Zhang |first1=Zhong |last2=Pu |first2=Liang |last3=Li |first3=Qian-shu |last4=King |first4=R. Bruce |title=The facile coupling of carbon monochalcogenides to ethenedichalcogenone ligands in binuclear iron carbonyl derivatives: a theoretical study |journal=New J. Chem. |date=2014 |volume=38 |issue=9 |pages=4282–4289 |doi=10.1039/C4NJ00740A}}
Formation
Ethenedithione can be made by the flash vacuum pyrolysis of 2,5-Dithiacyclopentylideneketene.
Also it has been made by dissociative ionization of tetrathiapentalenedione, and then neutralisation of ions produced.{{cite journal |last1=Sülzle |first1=Detlev |last2=Schwarz |first2=Helmut |title=Ethylenedithione(C2S2): Generation and Characterization by Neutralization-Reionization Mass Spectrometry |journal=Angewandte Chemie International Edition in English |date=October 1988 |volume=27 |issue=10 |pages=1337–1339 |doi=10.1002/anie.198813371}}
C2S2 is made along with carbon subsulfide and carbon monosulfide, in an electric discharge in carbon disulfide vapour.{{cite journal |last1=Bohn |first1=Robert B. |last2=Hannachi |first2=Yacine |last3=Andrews |first3=Lester |title=Production and reactions of triplet CS: matrix infrared and ultraviolet spectra of C2S2 |journal=Journal of the American Chemical Society |date=July 1992 |volume=114 |issue=16 |pages=6452–6459 |doi=10.1021/ja00042a024}}
Properties
In its ground state it is a triplet state (3Σg−).{{Cite journal |last=Ma |first=Ngai Ling |last2=Wong |first2=Ming Wah |date=1998-12-31 |title=Ethenedithione (S=C=C=S): Does It Obey Hund's Rule? |journal=Angewandte Chemie International Edition |language=en |volume=37 |issue=24 |pages=3402–3404 |doi=10.1002/(SICI)1521-3773(19981231)37:24<3402::AID-ANIE3402>3.0.CO;2-S |issn=1433-7851}} Ethenedithione can be trapped in a matrix of solid argon without decomposition.
The infrared spectrum contains a prominent line at 1179.3 cm−1 due to asymmetric C=S stretch of the most common isotopes.
Over 60 K, ethenedithione polymerises.{{cite journal |last1=Yranzo |first1=Gloria I. |last2=Elguero |first2=José |last3=Flammang |first3=Robert |last4=Wentrup |first4=Curt |title=Formation of Cumulenes, Triple-Bonded, and Related Compounds by Flash Vacuum Thermolysis of Five-Membered Heterocycles |journal=European Journal of Organic Chemistry |date=June 2001 |volume=2001 |issue=12 |pages=2209–2220 |doi=10.1002/1099-0690(200106)2001:12<2209::AID-EJOC2209>3.0.CO;2-X}} Possible polymerisation products include polythiene.{{cite journal |last1=Zmolek |first1=Peter B. |last2=Sohn |first2=Honglae |last3=Gantzel |first3=Peter K. |last4=Trogler |first4=William C. |title=Photopolymerization of Liquid Carbon Disulfide Produces Nanoscale Polythiene Films |journal=Journal of the American Chemical Society |date=1 February 2001 |volume=123 |issue=6 |pages=1199–1207 |doi=10.1021/ja003200j}}