| Revision as of 11:38, 5 December 2011 editBeetstra (talk | contribs)Edit filter managers, Administrators172,031 edits Saving copy of the {{chembox}} taken from revid 463171219 of page Pentacene for the Chem/Drugbox validation project (updated: ''). |
Latest revision as of 06:18, 25 November 2024 edit Citation bot (talk | contribs)Bots5,429,468 edits Added bibcode. | Use this bot. Report bugs. | Suggested by Headbomb | Linked from Misplaced Pages:WikiProject_Academic_Journals/Journals_cited_by_Wikipedia/Sandbox | #UCB_webform_linked 167/308 |
| Line 1: |
Line 1: |
|
|
{{Short description|Hydrocarbon compound (C22H14) made of 5 fused benzene rings}} |
|
{{ambox | text = This page contains a copy of the infobox ({{tl|chembox}}) taken from revid of page ] with values updated to verified values.}} |
|
|
{{chembox |
|
{{chembox |
|
|
| Watchedfields = changed |
|
| verifiedrevid = 449964177 |
|
|
|
| verifiedrevid = 464197831 |
|
| ImageFile_Ref = {{chemboximage|correct|??}} |
|
| ImageFile_Ref = {{chemboximage|correct|??}} |
|
| ImageFile = Pentacene.png |
|
| ImageFile = Pentacene.svg |
|
| ImageSize = 200px |
|
| ImageSize = 200px |
|
|
| ImageAlt = Skeletal formula of pentacene |
|
| ImageFile1 = Pentacene-3D-balls.png |
|
|
|
| ImageFile1 = Pentacene molecule spacefill.png |
|
| ImageSize1 = 220px |
|
| ImageSize1 = 220px |
|
|
| ImageAlt1 = Space-filling model of the pentacene molecule |
|
| Section1 = {{Chembox Identifiers |
|
|
|
| PIN = Pentacene <!-- Nomenclature of Organic Chemistry – IUPAC Recommendations and Preferred Names 2013 (Blue Book) --> |
|
|
| OtherNames = 2,3:6,7-Dibenzanthracene <br/>Benzonaphthacene<br/>Dibenzanthracene<br/>NSC 90784<br/>lin-Dibenzanthracene<br/>lin-Naphthoanthracene |
|
|
|Section1={{Chembox Identifiers |
|
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} |
|
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} |
|
| ChemSpiderID = 8347 |
|
| ChemSpiderID = 8347 |
| Line 18: |
Line 23: |
|
| CASNo_Ref = {{cascite|correct|CAS}} |
|
| CASNo_Ref = {{cascite|correct|CAS}} |
|
| CASNo = 135-48-8 |
|
| CASNo = 135-48-8 |
|
|
| UNII_Ref = {{fdacite|correct|FDA}} |
|
|
| UNII = 9FQU5HA0UY |
|
| PubChem = 8671 |
|
| PubChem = 8671 |
|
| ChEBI_Ref = {{ebicite|correct|EBI}} |
|
| ChEBI_Ref = {{ebicite|correct|EBI}} |
|
| ChEBI = 33148 |
|
| ChEBI = 33148 |
|
|
| EC_number = 205-193-7 |
|
|
| Beilstein = 1912418 |
|
|
| Gmelin = 733903 |
|
| SMILES = c1ccc2cc3cc4cc5ccccc5cc4cc3cc2c1 |
|
| SMILES = c1ccc2cc3cc4cc5ccccc5cc4cc3cc2c1 |
|
}} |
|
}} |
|
| Section2 = {{Chembox Properties |
|
|Section2={{Chembox Properties |
|
| Formula = C<sub>22</sub>H<sub>14</sub> |
|
| C = 22 | H = 14 |
|
|
| Appearance = Dark blue powder |
|
| MolarMass = 278.36 g/mol |
|
|
|
| Density = 1.3 g cm<sup>−3</sup> |
|
| Appearance = Dark powder |
|
|
|
| MeltingPt = > |
|
| Density = 1.3 g/cm<sup>3</sup> |
|
|
|
| MeltingPtC = 300 |
|
| MeltingPt = > 300 °C; sublimes at 372 °C |
|
|
|
| MeltingPt_notes= sublimes at 372 °C |
|
| BoilingPt = |
|
|
|
| BoilingPtC = 40-43 |
|
|
| BoilingPt_notes = at 0.15 torr |
|
| Solubility = |
|
| Solubility = |
|
|
| MagSus = -205.4 × 10<sup>−6</sup> cm<sup>3</sup> mol<sup>−1</sup> |
|
}} |
|
}} |
|
| Section3 = {{Chembox Structure |
|
|Section3={{Chembox Structure |
|
| CrystalStruct = ] |
|
| CrystalStruct = ] |
|
| SpaceGroup = P-1 |
|
| SpaceGroup = P-1 |
|
}} |
|
}} |
|
| Section7 = {{Chembox Hazards |
|
|Section7={{Chembox Hazards |
|
| MainHazards = |
|
| MainHazards = |
|
| FlashPt = |
|
| FlashPt = |
|
| Autoignition = |
|
| AutoignitionPt = |
|
}} |
|
}} |
|
}} |
|
}} |
|
|
|
|
|
'''Pentacene''' ({{chem2|C22H14}}) is a ] consisting of five linearly-fused ] ({{chem2|C6H6}}) ]. This highly ] compound is an ]. The compound generates ]s upon absorption of ultra-violet (]) or visible ]; this makes it very sensitive to ]. For this reason, this compound, which is a purple powder, slowly ] upon exposure to air and light. |
|
|
|
|
|
Structurally, pentacene is one of the linear ]s, the previous one being ] (four fused benzene rings) and the next one being ] (six fused benzene rings). In August 2009, a group of researchers from ] published experimental results of imaging a single ] of pentacene using an ].<ref name=afm1>{{cite web |title=Single molecule's stunning image |url=http://news.bbc.co.uk/2/hi/science/nature/8225491.stm |date=2009-08-28 |access-date=2009-08-28|work=]}}</ref><ref name=afm2>{{cite journal|doi=10.1126/science.1176210|title=The Chemical Structure of a Molecule Resolved by Atomic Force Microscopy|year=2009|author=Gross, L.|journal=]|volume=325|pages=1110–1114|pmid=19713523|last2=Mohn|first2=F|last3=Moll|first3=N|last4=Liljeroth|first4=P|last5=Meyer|first5=G|issue=5944|bibcode = 2009Sci...325.1110G |s2cid=9346745}}</ref> In July 2011, they used a modification of ] to experimentally determine the shapes of the ] molecular ].<ref>{{cite news |url=https://www.science.org/content/article/molecules-imaged-most-intimately |title= Molecules Imaged Most Intimately |author= Krieger, K. |date= 23 August 2011 |access-date= 29 June 2017|publisher= ] }}</ref><ref>{{cite journal |journal= ] |volume= 107 |issue= 8 |year= 2011 |pages= 86101–86104 |title= High-Resolution Molecular Orbital Imaging Using a ''p''-Wave STM Tip |doi= 10.1103/PhysRevLett.107.086101 |author1=Gross, L. |author2=Moll, N. |author3=Mohn, F. |author4=Curioni, A. |author5=Meyer, G. |author6=Hanke, F. |author7=Persson, M. |bibcode=2011PhRvL.107h6101G |pmid=21929180}}</ref> |
|
|
|
|
|
In 2012, pentacene-doped ] was shown to be effective as the amplifier medium for a room-temperature ].<ref>{{Cite journal | last1 = Brumfiel | first1 = G. | doi = 10.1038/nature.2012.11199 | title = Microwave laser fulfills 60 years of promise | journal = ] | year = 2012 | s2cid = 124247048 }}</ref> |
|
|
|
|
|
==Synthesis== |
|
|
] image of pentacene molecules on nickel.<ref>{{cite journal|journal=]|volume=7|issue=7|title=Pentacene on Ni(111): Room-temperature molecular packing and temperature-activated conversion to graphene|year=2015|last1=Dinca|first1=L. E.|last2=De Marchi|first2=F.|last3=MacLeod|first3=J. M.|last4=Lipton-Duffin|first4=J.|last5=Gatti|first5=R.|last6=Ma|first6=D.|last7=Perepichka|first7=D. F.|last8=Rosei|first8=F.|author-link7=Dmitrii Perepichka|pages=3263–3269|doi=10.1039/C4NR07057G|pmid=25619890|bibcode=2015Nanos...7.3263D}}</ref>]] |
|
|
] |
|
|
The compound, originally called '''dinaphthanthracene''' after ] and ] (modern nomenclature for polyacenes, including pentacene, was only introduced in 1939 by ]<ref>{{Citation |last=Clar |first=E. |title=Nomenclature of Polycyclic Hydrocarbons |date=1964 |work=Polycyclic Hydrocarbons: Volume 1 |pages=3–11 |editor-last=Clar |editor-first=E. |url=https://link.springer.com/chapter/10.1007/978-3-662-01665-7_1 |access-date=2024-11-11 |place=Berlin, Heidelberg |publisher=Springer |language=en |doi=10.1007/978-3-662-01665-7_1 |isbn=978-3-662-01665-7}}</ref><ref>{{Cite Q|Q67223987}}</ref>), was first synthesized in 1912 by British chemists ] and ].<ref name="MillsandMills">{{cite journal |last1=Mills |first1=William Hobson |author-link1=William Hobson Mills |last2=Mills |first2=Mildred |author-link2=Mildred May Gostling |date=1912 |title=The synthetical production of derivatives of dinaphthanthracene |url=https://zenodo.org/record/2012649 |journal=] |volume=101 |pages=2194–2208 |doi=10.1039/CT9120102194}}</ref><ref>{{cite journal|title=Polymorphism as an emerging design strategy for high performance organic electronics|last1=Chung|first1=Hyunjoong|last2=Diao|first2=Ying|journal=]|date=2016|volume=4|issue=18|pages=3915–3933|doi=10.1039/C5TC04390E|quote=Since its synthesis in 1912 to the categorization of at least four different polymorphs in 2003, pentacene has developed into a benchmark organic semiconductor due to its excellent thin film transistor performance}}</ref> A classic method for pentacene synthesis is by the ].<ref>{{cite journal|first = Karl|last = Elbs|author-link = Karl Elbs|year = 1886|title = Beiträge zur Kenntniss aromatischer Ketone. Erste Mittheilung|journal = ]|language = de|volume = 33|issue = 1|pages = 180–188|doi = 10.1002/prac.18860330119|url = https://zenodo.org/record/1427908}}</ref><ref name=breit>{{cite book|first1 = Eberhard|last1 = Breitmaier|first2 = Günther|last2 = Jung|year = 2005|chapter-url = https://books.google.com/books?id=Ld-AGnffxXIC&pg=PA183|title = Organische Chemie: Grundlagen, Stoffklassen, Reaktionen, Konzepte, Molekülstrukturen|edition = 5th|location = Stuttgart|publisher = ]|isbn = 9783135415055|chapter = 12.5.3 Elbs-Reaktion|language = de|page = 183}}</ref> |
|
|
|
|
|
] |
|
|
|
|
|
Pentacenes can also be prepared by ] of a small volatile component (]) from a suitable precursor at 150 °C.<ref name=Chen>{{cite journal|doi=10.1039/b616511g|pmid=17325807|title=A new type of soluble pentacene precursor for organic thin-film transistors|year=2007|last1=Chen|first1=Kew-Yu|journal=]|volume=2007|issue=10|pages=1065–1067|last2=Hsieh|first2=Hsing-Hung|last3=Wu|first3=Chung-Chih|last4=Hwang|first4=Jiunn-Jye|last5=Chow|first5=Tahsin J.|url=http://ntur.lib.ntu.edu.tw//bitstream/246246/148626/1/64.pdf}}</ref> |
|
|
|
|
|
] |
|
|
|
|
|
The precursor itself is prepared in three steps from two molecules of α,α,α',α'-tetrabromo-''o''-xylene with a 7-''tert''-butoxybicyclohepta-2,5-diene by first heating with ] in ] to undergo a series of ] and ] reactions to form the ring system, then hydrolysing the ''tert''-butoxy group to an ] and followed by its oxidation to the ].<ref name=Chen /> |
|
|
|
|
|
] |
|
|
|
|
|
The product is reported to have some solubility in ] and is therefore amenable to ]. Pentacene is soluble in hot chlorinated benzenes, such as ], from which it can be recrystallized to form platelets. |
|
|
|
|
|
==Pentacene derivatives== |
|
|
=== Monomeric pentacene derivatives === |
|
|
6,13-Substituted pentacenes are accessible through pentacenequinone by reaction with an aryl or alkynyl nucleophile (for example Grignard or organolithium reagents) followed by reductive aromatization.<ref>{{cite journal|doi=10.1021/ja01258a005|year=1942|last1=Allen|first1=C. F. H.|title=Action of Grignard Reagents on Certain Pentacenequinones, 6,13-Diphenylpentacene|last2=Bell|first2=Alan|journal=Journal of the American Chemical Society|volume=64|pages=1253–1260|issue=6|bibcode=1942JAChS..64.1253A }}</ref><ref>{{cite journal|doi=10.1021/jo01258a045|title=Electronic absorption and fluorescence of phenylethynyl-substituted acenes|year=1969|last1=Maulding|first1=D. R.|last2=Roberts|first2=Bernard G.|journal=The Journal of Organic Chemistry|volume=34|pages=1734–1736|issue=6}}</ref><ref>{{cite journal|doi=10.1002/asia.200900754|title=Synthesis of 1,2,3,4,8,9,10,11-Octasubstituted Pentacenequinone Derivatives and their Conversion into Substituted Pentacenes|pmid=20455241|year=2010|last1=Li|first1=Shi|last2=Zhou|first2=Lishan|last3=Nakajima|first3=Kiyohiko|last4=Kanno|first4=Ken-Ichiro|last5=Takahashi|first5=Tamotsu|journal=Chemistry: An Asian Journal|volume=5|issue=7|pages=1620–6}}</ref> Another method is based on homologization of ]s by transition metals (through zirconacyclopentadienes) <ref>{{cite journal|doi=10.1021/ja003130g|title=Straightforward Method for Synthesis of Highly Alkyl-Substituted Naphthacene and Pentacene Derivatives by Homologation|year=2000|last1=Takahashi|first1=Tamotsu|last2=Kitamura|first2=Masanori|last3=Shen|first3=Baojian|last4=Nakajima|first4=Kiyohiko|journal=Journal of the American Chemical Society|volume=122|pages=12876–12877|issue=51|bibcode=2000JAChS.12212876T }}</ref><ref>{{cite journal|doi=10.1021/jo060923y|title=Homologation Method for Preparation of Substituted Pentacenes and Naphthacenes|pmid=17025283|year=2006|last1=Takahashi|first1=Tamotsu|last2=Li|first2=Shi|last3=Huang|first3=Wenying|last4=Kong|first4=Fanzhi|last5=Nakajima|first5=Kiyohiko|last6=Shen|first6=Baojian|last7=Ohe|first7=Takahiro|last8=Kanno|first8=Ken-Ichiro|journal=The Journal of Organic Chemistry|volume=71|issue=21|pages=7967–77}}</ref><ref>{{cite journal|doi=10.1016/j.tetlet.2007.07.075|title=Cu(I)-mediated cycloaddition reaction of zirconacyclopentadienes with fumaronitrile and application for synthesis of monocyano-substituted pentacenes|year=2007|last1=Takahashi|first1=Tamotsu|last2=Li|first2=Yanzhong|last3=Hu|first3=Jinghan|last4=Kong|first4=Fanzhi|last5=Nakajima|first5=Kiyohiko|last6=Zhou|first6=Lishan|last7=Kanno|first7=Ken-Ichiro|journal=Tetrahedron Letters|volume=48|pages=6726–6730|issue=38}}</ref><ref>{{cite journal|doi=10.1021/jo7017284|pmid=17999529|title=Three-Step Synthesis of End-Substituted Pentacenes|year=2007|last1=Stone|first1=Matthew T.|last2=Anderson|first2=Harry L.|journal=The Journal of Organic Chemistry|volume=72|issue=25|pages=9776–8}}</ref><ref>{{cite journal|doi=10.1002/asia.200800312|title=Double Homologation Method for Substituted Soluble Pentacenes and Dimerization Behaviours of Pentacenes|pmid=19072938|year=2009|last1=Li|first1=Shi|last2=Li|first2=Zhiping|last3=Nakajima|first3=Kiyohiko|last4=Kanno|first4=Ken-Ichiro|last5=Takahashi|first5=Tamotsu|journal=Chemistry: An Asian Journal|volume=4|issue=2|pages=294–301}}</ref> Functionalization of pentacene has allowed for control of the solid-state packing of this chromophore.<ref>{{cite journal|last1=Anthony|first1=J. E.|last2=Brooks|first2=J. S. |author3=Eaton, D. L. |author4= Parkin, S. R. |title=Functionalized Pentacene: Improved Electronic Properties from Control of Solid-State Order|journal=Journal of the American Chemical Society|year=2001|volume=123|issue=38|pages=9482–9483|doi=10.1021/ja0162459|pmid=11562247|bibcode=2001JAChS.123.9482A }}</ref><ref>{{cite journal|last=Anthony|first=J. E.|author2=Eaton, D. L. |author3=Parkin, S. R. |title=A Road Map to Stable, Soluble, Easily Crystallized Pentacene Derivatives|journal=Organic Letters|year=2002|volume=4|issue=1|pages=15–18|doi=10.1021/ol0167356|pmid=11772079}}</ref> The choice of the substituents (both size and location of substitution on the pentacene) influences the solid-state packing and can be used to control whether the compound adopts 1-dimensional or 2-dimensional cofacial ] in the solid-state, as opposed to the herringbone packing observed for pentacene. |
|
|
|
|
|
Although pentacene's structure resembles that of other aromatic compounds like ], its ] properties are poorly defined; as such, pentacene and its derivatives are the subject of much research. |
|
|
|
|
|
A ]ic ] exists between ''6-methylene-6,13-dihydropentacene'' and 6-methylpentacene. |
|
|
|
|
|
:] |
|
|
{{clear}} |
|
|
This equilibrium is entirely in favor of the methylene compound. Only by heating a solution of the compound to 200 °C does a small amount of the pentacene develop, as evidenced by the emergence of a red-violet color. According to one study<ref>{{cite journal|doi=10.1021/ol062012g|title=Why 6-Methylpentacene Deconjugates but Avoids the Thermally Allowed Unimolecular Mechanism|year=2006|author=Norton, Joseph E.|journal=Organic Letters|volume=8|pages=4915–8|pmid=17020335|last2=Northrop|first2=BH|last3=Nuckolls|first3=C|last4=Houk|first4=KN|issue=21}}</ref> the ] for this equilibrium is not based on an ] ], but on a ] ] hydrogen migration. In contrast, ]s with the same central chemical motif easily aromatize. |
|
|
|
|
|
Pentacene reacts with elemental ] in ] to the compound '''hexathiapentacene'''.<ref>{{cite journal|doi=10.1021/ja066088j|title=Hexathiapentacene: Structure, Molecular Packing, and Thin-Film Transistors|year=2006|author=Briseno, Alejandro L.|journal=Journal of the American Chemical Society|volume=128|pages=15576–7|pmid=17147352|last2=Miao|first2=Q|last3=Ling|first3=MM|last4=Reese|first4=C|last5=Meng|first5=H|last6=Bao|first6=Z|last7=Wudl|first7=F|issue=49|bibcode=2006JAChS.12815576B }}.</ref> ] shows that all the carbon-to-sulfur ]s are roughly equal (170 ]); from this, it follows that ]s B and C with complete charge separation are more significant than structure A. |
|
|
|
|
|
:] |
|
|
{{clear}} |
|
|
In the crystal phase the molecules display ]s, whereby the distance between some sulfur atoms on neighboring molecules can become less (337 pm) than the sum of two ] (180 pm) |
|
|
|
|
|
Like the related ], this compound is studied in the field of ]s. |
|
|
|
|
|
The acenes may appear as planar and rigid molecules, but in fact they can be very distorted. The pentacene depicted below:<ref>{{cite journal|doi=10.1021/ja065935f|title=Synthesis, Structure, and Resolution of Exceptionally Twisted Pentacenes|year=2006|author=Lu, Jun|journal=Journal of the American Chemical Society|volume=128|pages=17043–50|pmid=17177456|last2=Ho|first2=DM|last3=Vogelaar|first3=NJ|last4=Kraml|first4=CM|last5=Bernhard|first5=S|last6=Byrne|first6=N|last7=Kim|first7=LR|last8=Pascal Jr|first8=RA|issue=51|bibcode=2006JAChS.12817043L }}</ref> |
|
|
|
|
|
:] |
|
|
{{clear}} |
|
|
has an end-to end twist of 144° and is sterically stabilized by the six ] groups. The compound can be resolved into its two ]s with an unusually high reported ] of 7400° although ] takes place with a ] of 9 hours. |
|
|
|
|
|
===Oligomers and polymers of pentacene=== |
|
|
] |
|
|
|
|
|
] and ] based on pentacene have been explored both synthetically as well as in device application settings.<ref>{{cite journal|last=Lehnherr|first=D.|author2=Tykwinski, R.R.|title=Oligomers and Polymers Based on Pentacene Building Blocks|journal=Materials|year=2010|volume=3|issue=4|pages=2772–2800|doi=10.3390/ma3042772|bibcode = 2010Mate....3.2772L |pmc=5445842|doi-access=free}}</ref><ref>{{cite journal|last=Lehnherr|first=D.|author2=Tykwinski, R. R.|title=Conjugated Oligomers and Polymers Based on Anthracene, Tetracene, Pentacene, Naphthodithiophene, and Anthradithiophene Building Blocks|journal=Australian Journal of Chemistry|year=2011|volume=64|issue=7|pages=919–929|doi=10.1071/CH11169}}</ref> Polymer light emitting diodes (]s) have been constructed using conjugated copolymers ('''1a–b''') containing fluorene and pentacene.<ref>{{cite journal|last=Tokito|first=S.|author2=Weinfurtner, K.-H. |author3=Fujikawa, H. |author4=Tsutsui, T. |author5= Taga, Y. |editor1-first=Zakya H|editor1-last=Kafafi|title=Acene containing polyfluorenes for red, green and blue emission in organic light-emitting diodes|journal=Proc. SPIE–Int. Opt. Soc. Eng.|year=2001|volume=4105|pages=69–74|doi=10.1117/12.416877|series=Organic Light-Emitting Materials and Devices IV|bibcode=2001SPIE.4105...69T|s2cid=96976350}}</ref> A few other conjugated pentacene polymers ('''2a–b''' and '''3''') have been realized based on ] and ] coupling reactions of a dibromopentacene monomer.<ref>{{cite journal|last=Okamoto|first=T.|author2=Bao, Z.|title=Synthesis of solution-soluble pentacene-containing conjugated copolymers|journal=Journal of the American Chemical Society|year=2007|volume=129|issue=34|pages=10308–10309|doi=10.1021/ja0725403|pmid=17685520|bibcode=2007JAChS.12910308O }}</ref><ref>{{cite journal|last=Okamoto|first=T.|author2=Okamoto, T. |author3=Jiang, Y. |author4=Qu, F. |author5=Mayer, A.C. |author6=Parmer, J.E. |author7=McGehee, M.D. |author8= Bao, Z. |title=Synthesis and characterization of pentacene– and anthradithiophene–fluorene conjugated copolymers synthesized by Suzuki reactions|journal=Macromolecules|year=2008|volume=41|issue=19|pages=6977–6980|doi=10.1021/ma800931a|bibcode = 2008MaMol..41.6977O }}</ref> Non-conjugated pentacene-based polymers have been synthesized via esterification of a pentacene diol monomer with bis-acid chlorides to form polymers '''4a–b'''.<ref name="Lehnherr 2007 4583–4586">{{cite journal|last=Lehnherr|first=D.|author2=Tykwinski, R. R.|title=Pentacene Oligomers and Polymers: Functionalization of Pentacene to Afford Mono-, Di-, Tri-, and Polymeric Materials|journal=Organic Letters|year=2007|volume=9|issue=22|pages=4583–4586|doi=10.1021/ol702094d|pmid=17918951}}</ref><ref name="Lehnherr 2008 11449–11461">{{cite journal|last1=Lehnherr|first1=Dan|last2=McDonald|first2=Robert|last3=Ferguson|first3=Michael J.|last4=Tykwinski|first4=Rik R.|title=Synthesis of soluble oligo- and polymeric pentacene-based materials|journal=Tetrahedron|volume=64|issue=50|year=2008|pages=11449–11461|issn=0040-4020|doi=10.1016/j.tet.2008.09.041}}</ref> |
|
|
|
|
|
] |
|
|
<br /> |
|
|
Various synthetic strategies have been employed to form conjugated oligomers of pentacene '''5a–c''' including a one-pot-four-bond forming procedure which provided a solution-processable conjugated pentacene dimer ('''5c''') which exhibited photoconductive gain >10,<ref>{{cite journal|last=Lehnherr|first=D.|author2=Gao, J. |author3=Hegmann, F. A. |author4= Tykwinski, R. R. |title=Synthesis and Electronic Properties of Conjugated Pentacene Dimers|journal=Organic Letters|year=2008|volume=10|issue=21|pages=4779–4782|doi=10.1021/ol801886h|pmid=18823120}}</ref> placing its performance within the same order of magnitude as thermally evaporated films of non-functionalized pentacene which exhibited photoconductive gain >16 using analogous measurement techniques.<ref>{{cite journal|last=Gao|first=J.|author2=Hegmann, F. A|title=Bulk photoconductive gain in pentacene thin films|journal=Applied Physics Letters|year=2008|volume=93|issue=22|pages=223306|doi=10.1063/1.3043431|bibcode = 2008ApPhL..93v3306G }}</ref> A modular synthetic method to conjugated pentacene di-, tri- and tetramers ('''6–8''') has been reported which is based on homo- and cross-coupling reactions of robust dehydropentacene intermediates.<ref>{{cite journal|last=Lehnherr|first=D.|author2=Murray, A. H. |author3=McDonald, R. |author4= Tykwinski, R.R. |title=A Modular Synthetic Approach to Conjugated Pentacene Di-, Tri-, and Tetramers|journal=Angewandte Chemie International Edition|year=2010|volume=49|issue=35|pages=6190–6194|doi=10.1002/anie.201000555 |pmid=20645363}}</ref> Non-conjugated oligomers '''9–10''' based on pentacene have been synthesized,<ref name="Lehnherr 2007 4583–4586"/><ref name="Lehnherr 2008 11449–11461"/> including dendrimers '''9–10''' with up to 9 pentacene moieties per molecule with molar absorptivity for the most intense absorption > 2,000,000 M<sup>−1</sup>•cm<sup>−1</sup>. Dendrimers '''11–12''' were shown to have improved performance in devices compared to analogous pentacene-based polymers '''4a–b''' in the context of photodetectors.<ref>{{cite journal|last=Lehnherr|first=D.|author2=Gao, J. |author3=Hegmann, F. A. |author4= Tykwinski, R. R. |title=Pentacene-based dendrimers: synthesis and thin film photoconductivity measurements of branched pentacene oligomers|journal=Journal of Organic Chemistry|year=2009|volume=74|issue=14|pages=5017–5024|doi=10.1021/jo9007089|pmid=19489566}}</ref> |
|
|
|
|
|
] |
|
|
] |
|
|
|
|
|
==Materials research== |
|
|
Pentacenes have been examined as potential ]s. The pentacenoquinone displayed below is ] and when mixed with ] a ] of 8 is reached.<ref>{{cite journal|doi=10.1021/ol062999m|title=Synthesis and Characterization of Fluorescent Acenequinones as Dyes for Guest−Host Liquid Crystal Displays|year=2007|author=Chen, Zhihua|journal=Organic Letters|volume=9|pages=997–1000|pmid=17298074|last2=Swager|first2=TM|issue=6}}</ref><ref>in the synthesis of this compound, the starting material is treated with ] and ]. DTP converts the oxo-norbornadiene to an intermediary ]. The second step is oxidation by ]</ref> Longer acenes align better in the ] ] phase. |
|
|
|
|
|
:] |
|
|
{{clear}} |
|
|
Combined with ], pentacene is used in the development of organic photovoltaic prototypes.<ref>{{cite journal|doi=10.1063/1.2749863|title=Nanoimprinted large area heterojunction pentacene-C photovoltaic device|year=2007|author=Dissanayake, D. M. Nanditha M.|journal=Applied Physics Letters|volume=90|pages=253502|issue=25|bibcode = 2007ApPhL..90y3502D |url=http://epubs.surrey.ac.uk/7807/1/fulltext.pdf}}</ref><ref>''Efficiently Organic: Researchers Use Pentacene To Develop Next-generation Solar Power'' sciencedaily.com </ref> Organic photovoltaic cells are cheaper and more flexible than traditional inorganic cells, which could potentially open doors to solar cells in new markets.<ref>{{Cite news|url=https://www.sciencedaily.com/releases/2004/12/041220005834.htm|title=Efficiently Organic: Researchers Use Pentacene To Develop Next-generation Solar Power|work=ScienceDaily|access-date=2017-11-14|language=en}}</ref> |
|
|
|
|
|
Pentacene is a popular choice for research on organic ]s and ]s, being 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 cm<sup>2</sup>/(V·s), which exceeds that of amorphous silicon.<ref>{{cite journal|doi=10.1002/cphc.200700177|title=Organic Electronic Devices and Their Functional Interfaces|year=2007|author=Norbert Koch|journal=ChemPhysChem|volume=8|pages=1438–55|pmid=17539032|issue=10}}</ref><ref name=sc>{{cite journal|journal=Sci. Technol. Adv. Mater. |volume=10|year=2009|page= 024314|doi=10.1088/1468-6996/10/2/024314|pmid=27877287|pmc=5090444|title=Organic field-effect transistors using single crystals|author1=Tatsuo Hasegawa |author2=Jun Takeya |name-list-style=amp |issue=2|bibcode=2009STAdM..10b4314H}}</ref><ref name=pc>{{cite journal|journal=Sci. Technol. Adv. Mater. |volume=10|year=2009|page= 024313|doi=10.1088/1468-6996/10/2/024313|pmid=27877286|title=Organic semiconductors for organic field-effect transistors|author=Yoshiro Yamashita|issue=2|bibcode=2009STAdM..10b4313Y|pmc=5090443}}</ref> |
|
|
|
|
|
Pentacene, as well as other organic conductors, is subject to rapid oxidation in air, which precludes commercialization. If the pentacene is preoxidized, the pentacene-quinone is a potential gate insulator, then the mobility can approach that of ] – the highest-mobility organic semiconductor – namely, 40 cm<sup>2</sup>/(V·s). This pentacene oxidation technique is akin to the silicon oxidation used in the silicon electronics.<ref name=sc/> |
|
|
|
|
|
==See also== |
|
|
* ] |
|
|
|
|
|
==References== |
|
|
{{reflist|30em}} |
|
|
|
|
|
==External links== |
|
|
*, retrieved Apr. 17, 2006 |
|
|
*, New Scientist, ''2 December 2007'' |
|
|
*, IBM images Pentacene, the first molecule imaged in detail ''29 August 2009'' |
|
|
|
|
|
{{PAHs}} |
|
|
|
|
|
] |
|
|
] |
|
|
] |
|
|
] |