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Diphenyl disulfide

Diphenyl disulfide

General
Systematic name	Diphenyl disulfide
Other names	Phenyl disulfide
Molecular formula	C₁₂H₁₀S₂
SMILES	C1(SSC2=CC=CC=C2)=CC=CC=C1
Molar mass	218.36 g/mol
Appearance	Colourless crystals
CAS number	[882-33-7]
Properties
Density and phase	? g/cm³
Solubility in water	Insoluble
Other solvents	Diethyl ether, Benzene, Carbon disulfide, THF
Melting point	61–62 °C
Boiling point	? °C
Structure
Crystal structure
Dipole moment	0 D
Hazards
MSDS	External MSDS
Main hazards	Flammable
NFPA 704
Flash point	? °C
R/S statement	R: 36/37/38 S: 26
RTECS number	SS6825000
Supplementary data page
Structure and properties	n, ε_r, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Related compounds
Related compounds	C₆H₅SH, (CH₃)₂S₂, Diphenyl diselenide
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Diphenyl disulfide is the chemical compound with the formula [C₆H₅S]₂. This colorless crystalline material is often abbreviated Ph₂S₂. It is one of the most popular organic disulfides used in organic synthesis. Minor comtamination by thiophenol is responsible for the disagreeable odour associated with this compound.

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1 Preparation and structure
2 Reactions
3 References

Preparation and structure

Ph₂S₂ is usually prepared by the oxidation of thiophenol:

2 PhSH + I₂ → Ph₂S₂ + 2 HI

Hydrogen peroxide can also be used as the oxidant.^[1] Ph₂S₂ is rarely prepared in the laboratory because it is inexpensive, and the precursor has a disagreeable odour.

Like most organic disulfides, the C₂S₂ core of Ph₂S₂ is non-planar with a dihedral angle approaching 85°.

Reactions

Ph₂S₂ is mainly used in organic synthesis as a source of the PhS substituent.^[2] 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

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

Chlorination

Ph₂S₂ reacts with chlorine to give phenylsulfenyl chloride PhSCl (Zincke disulfide cleavage). This species is difficult to isolate, so it is usually generated in situ.

Catalyst for photoisomerisation of alkenes

Ph₂S₂catalyzes the cis-trans isomerization of alkenes under UV-irradiation.^[3]

Oxidation

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

References

^ 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". Org. Synth. 80: 184.
^ Byers, J. H. "Diphenyl Disulfide" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. DOI: 10.1002/047084289.
^ Thalmann, A. Oertle, K.; Gerlach, H. (1990). "Ricinelaidic Acid Lactone". Org. Synth.; Coll. Vol. 7: 470.
^ Field, L.; Locke, J. M. (1973). "Methyl Benzenesulfinate". Org. Synth.; Coll. Vol. 5: 723.

Categories: Organic disulfides | Aromatic compounds

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Diphenyl_disulfide". A list of authors is available in Wikipedia.