Английская Википедия:Dithiolium salt

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Файл:Dithiolium isomers.png
1,2- and 1,3-dithiolium cations.

Dithiolium salts are compounds of the formula [(RC)3S2]+X (R = H, alkyl, aryl, etc.). These salts consist of a planar organic cation with a variety of anions such as halides. The five-membered ring cations are observed in either of two isomers, 1,2- and 1,3-dithiolium cations. These cations differ with respect to the relative positions of the pair of sulfur atoms. Both isomers feature a planar ring, which is aromatic owing to the presence of 6π electrons.[1] For example, the 1,2-ditholium ring can be represented as an allyl cation of the three carbons,[2] with each sulfur atom donating one of its lone pairs of electrons to give a total of three pairs.

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Structure of diphenyl-1,2-dithiolium cation (as its bisulfate salt). Selected distances: S-S = 2.019(5); S-C=173(1); Cring-Cring = 1.38(1) Å.[3]

Preparation, occurrence, reactions

1,2-Dithiolium cations have been prepared from 1,3-diketones by treatment with H2S and oxidants such as bromine.[2]

Шаблон:Chem2

1,3-Dithiolium cations are often prepared by alkylation of the corresponding unsaturated dithio- or trithiocarbonates:

Шаблон:Chem2

The analogous reaction of electrophiles with 1,2-dithiole-2-ones affords 1,2-dithiolium cations.

References