Tetracene, also called naphthacene, is a polycyclic aromatic hydrocarbon. It has the appearance of a pale orange powder. Tetracene is the four-ringed member of the series of acenes.
In 1884, W. Roser attempted to synthesize a compound called "Aethindiphtalyls" (literally "ethyne diphthalyl")[2] by heating 3 parts of phthalic anhydride, 3 parts of succinic acid and one part of sodium acetate according to Siegmund Gabriel's procedure.[3] And then he found that there was a brick-red byproduct was produced in a large amount in the reaction, which was called "Isoäthindiphtalid" (literally "Isoethyne diphthalide") and founded to be an isomer of "Aethindiphtalyls". In 1898, Gabriel and Ernst Leupold did a study on the byproduct and confirmed it was a new class of compound containing 4 rings.[4]
In the same document, Gabriel and Leupold reported their synthesis of tetracene by condensating two moles of phthalic anhydride with a mole of succinic acid into a quinone then reduced with zinc dust.[4][5] They named in naphthacene, likely as portmanteau of naphthalene and anthracene. Modern nomenclature for polyacenes, including tetracene, was introduced by Erich Clar in 1939.[6][7] Clar also developed a new route to synthesize tetracene from the Friedel-Crafts acrylation between phthalic anhydride and tetralin catalyzed by AlCl3, ZnCl2 and NaCl involving Clemmensen reduction, forming 5,12-dihydrotetracene then dehydrogenated by chloranil to form tetracene.[8]
The synthetic route of tetracene developed by Erich Clar.
German physicistJan Hendrik Schön claimed to have developed an electrically pumped laser based on tetracene during his time at Bell Labs (1997–2002). However, his results could not be reproduced, and this is considered to be a scientific fraud.[9]
In May 2007, Japanese researchers from Tohoku University and Osaka University reported an ambipolar light-emitting transistor made of a single tetracene crystal.[10] Ambipolar means that the electric charge is transported by both positively charged holes and negatively charged electrons.
In 2024, it was used to produce lower-energy excitations in solar cells in a process known as singlet fission. An interface layer between tetracene and silicon transfers them into the silicon layer, where most of their energy can be converted into electricity.[11]
^E. Clar (6 December 1939). "Vorschläge zur Nomenklatur kondensierter Ringsysteme (Aromatische Kohlenwasserstoffe, XXVI. Mitteil.)". Berichte der Deutschen Chemischen Gesellschaft zu Berlin. Abteilung B, Abhandlungen. 72 (12): 2137–2139. doi:10.1002/CBER.19390721219. ISSN0365-9488. WikidataQ67223987.
^Clar, E. (1942). "Eine neue Synthese des Tetracens". Chemische Berichte. 75 (10): 1271–1273. doi:10.1002/cber.19420751015.
