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.

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 dmit2-, reduction of CS2 was thought to give tetrathiooxalate (Na2C2S4).

The dianion C3S52- 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:
 * [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

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