Diphenyl disulfide is the chemical compound with the formula (C6H5S)2. This colorless crystalline material is often abbreviated Ph2S2. It is one of the more commonly encountered organic disulfides in organic synthesis. Minor contamination by thiophenol is responsible for the disagreeable odour associated with this compound.

Diphenyl disulfide
Names
Preferred IUPAC name
1,1′-Disulfanediyldibenzene
Other names
Disulfanyldibenzene
Diphenyl disulfide
Phenyl disulfide
1,2-Diphenyldisulfane (not recommended)
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.011.752 Edit this at Wikidata
EC Number
  • 212-926-4
RTECS number
  • SS6825000
UNII
  • InChI=1S/C12H10S2/c1-3-7-11(8-4-1)13-14-12-9-5-2-6-10-12/h1-10H checkY
    Key: GUUVPOWQJOLRAS-UHFFFAOYSA-N checkY
  • InChI=1/C12H10S2/c1-3-7-11(8-4-1)13-14-12-9-5-2-6-10-12/h1-10H
    Key: GUUVPOWQJOLRAS-UHFFFAOYAY
  • c1ccc(cc1)SSc2ccccc2
Properties
C12H10S2
Molar mass 218.33 g·mol−1
Appearance Colorless crystals
Melting point 61 to 62 °C (142 to 144 °F; 334 to 335 K)
Insoluble
Solubility in other solvents Soluble in diethyl ether, benzene, carbon disulfide, and THF
Structure
0 D
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Flammable
GHS labelling:[1]
GHS07: Exclamation mark
Warning
H315, H319, H335
P261, P264, P271, P273, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P391, P403+P233, P405, P501
Related compounds
Related compounds
Thiophenol,
Dimethyl disulfide,
Diphenyl diselenide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Preparation and structure

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Diphenyl disulfide is usually prepared by the oxidation of thiophenol:

2 PhSH + I2 → Ph2S2 + 2 HI

Hydrogen peroxide can also be used as the oxidant.[2] Ph2S2 is rarely prepared in the laboratory because it is inexpensive, and the precursor has a disagreeable odour.

Like most organic disulfides, the C–S–S–C core of Ph2S2 is non-planar with a dihedral angle approaching 85°.[3]

 
Ball-and-stick model of diphenyl disulfide. The S-S bond distance is 2.03 Å.

Reactions

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Ph2S2 is mainly used in organic synthesis as a source of the PhS substituent.[4] A typical reaction entails the formation of PhS-substituted carbonyl compounds via the enolate:

RC(O)CHLiR' + Ph2S2 → RC(O)CH(SPh)R' + LiSPh

Reduction

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Ph2S2 undergoes reduction, a reaction characteristic of disulfides:

Ph2S2 + 2 M → 2 MSPh (M = Li, Na, K)

Hydride reagents such as sodium borohydride and super hydride can also be used as reductants. The salts PhSM are sources of the potent nucleophile PhS. Most alkyl halides, RX (X = halide) convert it to the thioethers with the general formula RSPh. Analogously, protonation of MSPh gives thiophenol:

PhSM + HCl → HSPh + MCl

Halogenation

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Ph2S2 reacts with chlorine to give phenylsulfenyl chloride PhSCl (Zincke disulfide cleavage). This species is usually generated and used in situ. With xenon difluoride, Ph2S2 reacts to give phenylsulfur pentafluoride.[5]

Catalyst for photoisomerization of alkenes

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Ph2S2 catalyzes the cis-trans isomerization of alkenes under UV-irradiation.[6]

Oxidation

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Oxidation of Ph2S2 with lead(IV) acetate (Pb(OAc)4) in methanol affords the sulfinite ester PhS(O)OMe.[7]

References

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  1. ^ "Diphenyl disulfide". pubchem.ncbi.nlm.nih.gov. Retrieved 13 December 2021.
  2. ^ Ravikumar,K. S.; Kesavan, V.; Crousse, B.; Bonnet-Delpon, D.; Bégué, J.-P. (2003). "Mild and Selective Oxidation of Sulfur Compounds in Trifluoroethanol: Diphenyl Disulfide and Methyl Phenyl Sulfoxide". Organic Syntheses. 80: 184. doi:10.15227/orgsyn.080.0184.
  3. ^ Lee, J. D.; Bryant, M. W. R. (1969). "The Crystal Structure of Diphenyl Disulphide". Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry. 25 (10): 2094–2101. Bibcode:1969AcCrB..25.2094L. doi:10.1107/S0567740869005188.
  4. ^ Byers, J. H. (2004). "Diphenyl Disulfide". In J. Wiley & Sons (ed.). Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette). New York. doi:10.1002/047084289X. hdl:10261/236866. ISBN 9780471936237.{{cite book}}: CS1 maint: location missing publisher (link).
  5. ^ Sergeeva, Tatiana A.; Dolbier, William R. (2004-07-01). "A New Synthesis of Pentafluorosulfanylbenzene". Organic Letters. 6 (14): 2417–2419. doi:10.1021/ol0491991. ISSN 1523-7060. PMID 15228293.
  6. ^ Thalmann, A. Oertle, K.; Gerlach, H. (1990). "Ricinelaidic Acid Lactone". Organic Syntheses{{cite journal}}: CS1 maint: multiple names: authors list (link); Collected Volumes, vol. 7, p. 470.
  7. ^ Field, L.; Locke, J. M. (1973). "Methyl Benzenesulfinate". Organic Syntheses; Collected Volumes, vol. 5, p. 723.