Pentacene

Pentacene

Names
Preferred IUPAC name Pentacene
Identifiers
CAS Number	135-48-8 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:33148 Y
ChemSpider	8347 Y
ECHA InfoCard	100.004.722
PubChem CID	8671
InChI InChI=1S/C22H14/c1-2-6-16-10-20-14-22-12-18-8-4-3-7-17(18)11-21(22)13-19(20)9-15(16)5-1/h1-14H Y Key: SLIUAWYAILUBJU-UHFFFAOYSA-N Y InChI=1/C22H14/c1-2-6-16-10-20-14-22-12-18-8-4-3-7-17(18)11-21(22)13-19(20)9-15(16)5-1/h1-14H Key: SLIUAWYAILUBJU-UHFFFAOYAR
SMILES c1ccc2cc3cc4cc5ccccc5cc4cc3cc2c1
Properties
Chemical formula	C22H14
Molar mass	278.36 g/mol
Appearance	Dark blue powder
Density	1.3 g/cm3
Melting point	> 300 °C; sublimes at 372 °C
Magnetic susceptibility (χ)	-205.4·10−6 cm3/mol
Structure
Crystal structure	Triclinic
Space group	P-1
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

Pentacene is a polycyclic aromatic hydrocarbon consisting of five linearly-fused benzene rings. This highly conjugated compound is an organic semiconductor. The compound generates excitons upon absorption of ultra-violet (UV) or visible light; this makes it very sensitive to oxidation. For this reason, this compound, which is a purple powder, slowly degrades upon exposure to air and light.

Structurally, pentacene is one of the linear acenes, the previous one being tetracene (four fused benzene rings) and the next one being hexacene (six fused benzene rings). In August 2009, a group of researchers from IBM published experimental results of imaging a single molecule of pentacene using an atomic force microscope. In July 2011, they used a modification of scanning tunneling microscopy to experimentally determine the shapes of the highest occupied and lowest unoccupied molecular orbitals.

In 2012, pentacene-doped p-terphenyl was shown to be effective as the amplifier medium for a room-temperature maser.

In February 2014, NASA announced a greatly upgraded database for tracking polycyclic aromatic hydrocarbons (PAHs), including Pentacene, in the universe. According to scientists, more than 20% of the carbon in the universe may be associated with PAHs, possible starting materials for the formation of life. PAHs seem to have been formed shortly after the Big Bang, are widespread throughout the universe, and are associated with new stars and exoplanets.