Diphenyl diselenide

Diphenyl diselenide

Names
IUPAC name Diphenyl diselenide
Other names Phenyl diselenide
Identifiers
CAS Number	1666-13-3 Y
3D model (Jmol)	Interactive image
ChemSpider	14710 Y
ECHA InfoCard	100.015.256
PubChem CID	15460
RTECS number	JM9152500
InChI InChI=1S/C12H10Se2/c1-3-7-11(8-4-1)13-14-12-9-5-2-6-10-12/h1-10H Y Key: YWWZCHLUQSHMCL-UHFFFAOYSA-N Y InChI=1/C12H10Se2/c1-3-7-11(8-4-1)13-14-12-9-5-2-6-10-12/h1-10H Key: YWWZCHLUQSHMCL-UHFFFAOYAK
SMILES c1ccc(cc1)[Se][Se]c2ccccc2
Properties
Chemical formula	C12H10Se2
Molar mass	312.15 g·mol−1
Appearance	Orange powder
Density	1.84 g/cm3
Melting point	59 to 61 °C (138 to 142 °F; 332 to 334 K)
Solubility in water	Insoluble
Solubility in other solvents	Dichloromethane
Structure
Coordination geometry	90° at Se C2 symmetry
Dipole moment	0 D
Hazards
Main hazards	Toxic
R-phrases	R23/25 R33 R50/53
S-phrases	S20/21 S28 S45 S60 S61
Related compounds
Related compounds	Ph2S2, C6H5SeH
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Diphenyl diselenide is the chemical compound with the formula (C₆H₅)₂Se₂, abbreviated Ph₂Se₂ This orange-coloured solid is the oxidized derivative of benzeneselenol. It is used as a source of the PhSe unit in organic synthesis.

Ph₂Se₂ is prepared by the oxidation of benzeneselenoate, the conjugate base of benzeneselenol which is generated via the Grignard reagent:

The molecule has idealized C₂-symmetry, like hydrogen peroxide and related molecules. The Se-Se bond length of 2.29 Å the C-Se-Se-C dihedral angle is 82° and the C-Se-Se angles are near 110°.

A reaction characteristic of Ph₂Se₂ is its reduction:

PhSeNa is a useful nucleophile used to introduce the phenylselenyl group by nucleophilic substitution of alkyl halides, alkyl sulfonates (mesylates or tosylates) and epoxides. The example below was taken from a synthesis of morphine.

Another characteristic reaction is chlorination:

PhSeCl is a powerful electrophile, used to introduce PhSe groups by reaction with a variety of nucleophiles, including enolates, enol silyl ethers, Grignard reagents, organolithium reagents, alkenes and amines. In the sequence below (early steps in the synthesis of Strychnofoline), a PhSe group is introduced by reaction of a lactam enolate with PhSeCl. This sequence is a powerful method for the conversion of carbonyl compounds to their α,β-unsaturated analogs.