Pentacene is a promising candidate for the use in organic thin film transistors and OFETs. It is one of the most thoroughly investigated conjugated organic molecules with a high application potential due to a hole mobility in OFETs of up to 5.5 cm2V-1s-1 (almost comparable to amorphous silicon).
Combined with buckminsterfullerene Pentacene is used in the development of organic photovoltaic devices.''
This equilibrium is entirely in favor of the methylene compound. Only by heating to a solution of the compound to 200°C does a small amount of the pentacane develop as evidenced by the emergence of a red-violet color. According to one study the reaction mechanism for this equilibrium is not based on an intramolecular 1,5-hydride shift but on a bimolecular free radical hydrogen migration. In contrast, isotoluenes with the same central chemical motif easily aromatize.
Pentacene reacts with elemental sulfur in 1,2,4-trichlorobenzene to the compound hexathiapentacene. X-ray crystallography shows that all the carbon-to-sulfur bond lengths are roughly equal (170 picometer) and from there it follows that resonance structures B and C with complete charge separation are more significant than structure A.
The acenes may appear as planar and rigid molecules, but in fact they can be very distorted. The pentacene depicted below:
has an end-to end twist of 144° and is sterically stabilized by the six phenyl groups. The compound can be resolved into its two enantiomers with an unusually high reported optical rotation of 7400° although racemization takes place with a chemical half-life of 9 hours.
US Patent Issued to Sony on Dec. 28 for "Dichroic Dye Composition, and Liquid-Crystal Composition and Liquid-Crystal Element Including Dichroic Dye" (Japanese Inventors)
Dec 30, 2010; ALEXANDRIA, Va., Dec. 30 -- United States Patent no. 7,857,991, issued on Dec. 28, was assigned to Sony Corp. (Tokyo). "Dichroic...