Sodium 1,3-dithiole-2-thione-4,5-dithiolate

Sodium 1,3-dithiole-2-thione-4,5-dithiolate is the organosulfur compound with the formula Na₂C₃S₅, abbreviated Na₂dmit. It is the sodium salt of the conjugate base of the 4,5-bis(sulfanyl)-1,3-dithiole-2-thione. The salt is a precursor to dithiolene complexes and tetrathiafulvalenes.^[1]

Sodium 1,3-dithiole-2-thione-4,5-dithiolate

Names
Preferred IUPAC name Disodium 2-sulfanylidene-2H-1,3-dithiole-4,5-bis(thiolate)
Identifiers
CAS Number	54995-24-3
3D model (JSmol)	Interactive image
ChemSpider	9405301
PubChem CID	129790408
InChI InChI=1S/C3H2S5.2Na/c4-1-2(5)7-8-3(1)6;;/h4-5H;;/q;2*+1/p-2 Key: JTYXTCNFMIILHG-UHFFFAOYSA-L InChI=1S/C3H2S5.2Na/c4-1-2(5)8-3(6)7-1;;/h4-5H;;/q;2*+1/p-2
SMILES C1([S-])SC(SC=1[S-])=S.[Na+].[Na+]
Properties
Chemical formula	C3Na2S5
Molar mass	242.31 g·mol−1
Appearance	yellow solid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Reduction of carbon disulfide with sodium affords sodium 1,3-dithiole-2-thione-4,5-dithiolate together with sodium trithiocarbonate:

4 Na + 4 CS₂ → Na₂C₃S₅ + Na₂CS₃

Before the characterization of dmit^2-, reduction of CS₂ was thought to give tetrathiooxalate (Na₂C₂S₄).^[2]

The dianion C₃S₅^2- is purified as the tetraethylammonium salt of the zincate complex [Zn(C₃S₅)₂]^2-. This salt converts to the bis(thioester) upon treatment with benzoyl chloride:^[3][1]

[N(C₂H₅)₄]₂[Zn(C₃S₅)₂] + 4 C₆H₅COCl → 2 C₃S₃(SC(O)C₆H₅)₂ + [N(C₂H₅)₄]₂[ZnCl₄]

Cleavage of the thioester with sodium methoxide gives sodium 1,3-dithiole-2-thione-4,5-dithiolate:

C₃S₃(SC(O)C₆H₅)₂ + 2 NaOCH₃ → Na₂C₃S₅ + 2 C₆H₅CO₂Me

Structure of [Zn(dmit)₂]^2-.^[4]

Na₂dmit undergoes S-alkylation.^[5] Heating solutions of Na₂dmit gives the isomeric 1,2-dithioledithiolate.