A compound containing a benzene ring is often also referred to as aromatic compounds, this is due to the previously extracted from the plant, with an aromatic odor substances mostly contains a benzene ring. Later studies have shown that this is actually a misunderstanding, and substances containing benzene ring is not necessarily with an aromatic odor substance with an aromatic odor does not necessarily contain a benzene ring, he was retained but the wrong name. Containing only the two elements of the hydrocarbon aromatic compound is also known as "aromatics," If two or more benzene rings are connected via a common two vicinal carbon atoms of the "side by side", it has been "fused aromatic ring . " Called naphthyl such compounds the most simple one, it is composed by two benzene rings, is mothball the main ingredient.
Pentacene is a fused ring aromatic hydrocarbon, with the above mentioned two carcinogenic aromatic hydrocarbons as well as contains a unit of five benzene rings, just arranged in a slightly different way, the five ring which is side-by-side, which also It is the Chinese name meaning (see figure below). The English name of the pentacene Pentacene, Penta mean five the acene mean condensed aromatics.
Pentacene is mainly used for the preparation of the organic thin film transistor, in the field of microelectronics, and pentacene is a promising organic compounds, since the pentacene not dissolve in most organic solvents, and only slightly soluble in hot benzene solution therefore, pentacene can be done with hot benzene mobile phase by HPLC purity. Pentacene in order to be prepared as a thin film transistor, and must be used vapor-deposited film formation. So many foreign research institutions regarded research focus on the development of a soluble pentacene precursor, through dissolution after the film formation, and then the precursor heat decomposed into pentacene, final preparation of excellent performance and pentacene thin film, such the technology greatly accelerate the application speed pentacene posed by pentacene films display system eventually will gradually replace the current silicon system. Right picture: precursor by heat decomposition diagram: precursor thermal decomposition pentacene
Synthesis of pentacene process is relatively cumbersome, and pentacene easily oxidized, post-purification is himself or herself, there are currently two methods can be purified, is a traditional chemical purification, and its purity can be done: about 95%, and another species is purified by sublimation after the chemical purification pentacene placed in a high vacuum (10-4Pa) quartz glass tube, dye-sublimation recrystallization treatment, the method of processing amount is small, time-consuming, laborious, but the purity of 99% or more can be done .
Pentacene are mainly used in the preparation of the organic thin film transistor (organic thin film transistors), the current, the maximum hole transporting properties of the devices prepared through the use of its single crystal reaches 35 cm2/Vs (Reference ADV. Mater is 2007, 19, 688-692). device Vapor Deposition hole transport properties can reach 3.0cm2/Vs.