1,2,3,4-Tetraphenylnaphthalene

1,2,3,4-Tetraphenylnaphthalene is a polycyclic aromatic hydrocarbon commonly prepared in the undergraduate teaching laboratory as an introduction to the Diels-Alder reaction, in this case between benzyne, which acts as the dienophile, (generated in situ) and tetraphenylcyclopentadienone, which acts as the diene.[2] It has two crystalline forms, and therefore has two different melting points.

1,2,3,4-Tetraphenylnaphthalene[1]

Skeletal formula Ball-and-stick model
Names
IUPAC name 1,2,3,4-Tetra(phenyl)naphthalene
Identifiers
CAS Number	751-38-2^Y
3D model (JSmol)	Interactive image Interactive image
ChemSpider	62982^Y
ECHA InfoCard	100.151.838
PubChem CID	69783
UNII	AQ533SQ362^Y
CompTox Dashboard (EPA)	DTXSID90226070
InChI InChI=1S/C34H24/c1-5-15-25(16-6-1)31-29-23-13-14-24-30(29)32(26-17-7-2-8-18-26)34(28-21-11-4-12-22-28)33(31)27-19-9-3-10-20-27/h1-24H^Y Key: UCTTYTFENYGAPP-UHFFFAOYSA-N^Y InChI=1/C34H24/c1-5-15-25(16-6-1)31-29-23-13-14-24-30(29)32(26-17-7-2-8-18-26)34(28-21-11-4-12-22-28)33(31)27-19-9-3-10-20-27/h1-24H Key: UCTTYTFENYGAPP-UHFFFAOYAS
SMILES C1=CC=C(C=C1)C2=C(C(=C(C3=CC=CC=C32)C4=CC=CC=C4)C5=CC=CC=C5)C6=CC=CC=C6 c15ccccc1c(c2ccccc2)c(c3ccccc3)c(c4ccccc4)c5c6ccccc6
Properties
Chemical formula	C34H24
Molar mass	432.55 g/mol
Melting point	199 to 201 °C (390 to 394 °F; 472 to 474 K)
Hazards
R-phrases (outdated)	R36/37/38
S-phrases (outdated)	S26 S36
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is ^YN ?)
Infobox references

References

1. 1,2,3,4-Tetraphenylnaphthalene at Sigma-Aldrich
2. Organic Syntheses, Coll. Vol. 5, p.1037 (1973); Vol. 46, p.107 (1966). Link