Rubrene

Rubrene (5,6,11,12-tetraphenyltetracene) is the organic compound with the formula (C₁₈H₈(C₆H₅)₄. It is a red colored polycyclic aromatic hydrocarbon. Because of its distinctive optical and electrical properties, rubrene has been extensively studied. It has been used as a sensitiser in chemoluminescence and as a yellow light source in lightsticks.^[1]

Rubrene

Names
Preferred IUPAC name 5,6,11,12-Tetraphenyltetracene
Other names 5,6,11,12-Tetraphenylnaphthacene, rubrene
Identifiers
CAS Number	517-51-1 Y
3D model (JSmol)	Interactive image
ChemSpider	61510 Y
ECHA InfoCard	100.007.494
EC Number	208-242-0
PubChem CID	68203
CompTox Dashboard (EPA)	DTXSID8060161
InChI InChI=1S/C42H28/c1-5-17-29(18-6-1)37-33-25-13-14-26-34(33)39(31-21-9-3-10-22-31)42-40(32-23-11-4-12-24-32)36-28-16-15-27-35(36)38(41(37)42)30-19-7-2-8-20-30/h1-28H Y Key: YYMBJDOZVAITBP-UHFFFAOYSA-N Y InChI=1/C42H28/c1-5-17-29(18-6-1)37-33-25-13-14-26-34(33)39(31-21-9-3-10-22-31)42-40(32-23-11-4-12-24-32)36-28-16-15-27-35(36)38(41(37)42)30-19-7-2-8-20-30/h1-28H Key: YYMBJDOZVAITBP-UHFFFAOYAD
SMILES c5(c3c(c1ccccc1c(c2ccccc2)c3c(c4ccccc4)c6ccccc56)c7ccccc7)c8ccccc8
Properties
Chemical formula	C42H28
Molar mass	532.7 g/mol
Melting point	315 °C (599 °F; 588 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Electronic properties

As an organic semiconductor, the major application of rubrene is in organic light-emitting diodes (OLEDs) and organic field-effect transistors, which are the core elements of flexible displays. Single-crystal transistors can be prepared using crystalline rubrene, which is grown in a modified zone furnace on a temperature gradient. This technique, known as physical vapor transport, was introduced in 1998.^[2][3]

Rubrene holds the distinction of being the organic semiconductor with the highest carrier mobility, reaching 40 cm²/(V·s) for holes. This value was measured in OFETs prepared by peeling a thin layer of single-crystalline rubrene and transferring to a Si/SiO₂ substrate.^[4]

Crystal structure

Several polymorphs of rubrene are known. Crystals grown from vapor in vacuum can be monoclinic,^[5] triclinic,^[6] and orthorhombic motifs.^[7] Orthorhombic crystals (space group B_bam) are obtained in a closed system in a two-zone furnace at ambient pressure.^[8]

Synthesis

Rubrene is prepared by treating 1,1,3-Triphenyl-2-propyn-1-ol with thionyl chloride.^[9]

The resulting chloroallene undergoes dimerization and dehydrochlorination to give rubrene.^[10]

Redox properties

Rubrene, like other polycyclic aromatic molecules, undergoes redox reactions in solution. It oxidizes and reduces reversibly at 0.95 V and −1.37 V, respectively vs SCE. When the cation and anion are co-generated in an electrochemical cell, they can combine with annihilation of their charges, but producing an excited rubrene molecule that emits at 540 nm. This phenomenon is called electrochemiluminescence.^[11]