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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, εr, 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.

Additional recommended knowledge

Contents

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

  1. ^ 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. 
  2. ^ 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.
  3. ^ Thalmann, A. Oertle, K.; Gerlach, H. (1990). "Ricinelaidic Acid Lactone". Org. Synth.; Coll. Vol. 7: 470. 
  4. ^ Field, L.; Locke, J. M. (1973). "Methyl Benzenesulfinate". Org. Synth.; Coll. Vol. 5: 723. 
 
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.
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