{{Chembox |Name = Nonacene |ImageFile = Nonacene.svg |ImageSize = 250px |ImageName = Skeletal formula of nonacene |ImageFile1 = |ImageSize1 = 250px |ImageAlt1 = |PIN = Nonacene |Section1={{Chembox Identifiers |CASNo = |UNII_Ref = {{fdacite|correct|FDA}} |UNII = |PubChem = 6857587 |ChemSpiderID = 5256923 |ChEBI = 33170 |SMILES = C1=CC=C2C=C3C=C4C=C5C=C6C=C7C=C8C=C9C=CC=CC9=CC8=CC7=CC6=CC5=CC4=CC3=CC2=C1 |InChI = InChI=1S/C38H22/c1-2-6-24-10-28-14-32-18-36-22-38-20-34-16-30-12-26-8-4-3-7-25(26)11-29(30)15-33(34)19-37(38)21-35(36)17-31(32)13-27(28)9-23(24)5-1/h1-22H |InChIKey=UIFXPOUSHBMMEG-UHFFFAOYSA-N }} |Section2={{Chembox Properties | C=38 | H=22 }} }} '''Nonacene''' is an organic compound and a polycyclic aromatic hydrocarbon and the ninth member of the acene or polyacene family of linear fused benzene rings. Its chemical formula is {{chem2|C38H22}}.<ref>{{cite web |title=Nonacene |url=https://webbook.nist.gov/cgi/cbook.cgi?ID=C258366 |publisher=NIST |access-date=30 March 2026 |language=en}}</ref>
==Structure== Like other acenes, nonacene features a planar, rectilinear arrangement of nine fused benzene rings.<ref>{{cite web |title=ZFIN ChEBI: nonacene |url=https://zfin.org/action/ontology/term/CHEBI:33170#summary |publisher=zfin.org |access-date=30 March 2026}}</ref> This extended ''π''-conjugated system gives rise to its characteristic electronic properties.
As the number of fused benzene rings increases, the energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) decreases. For nonacene, this gap is significantly smaller than that of smaller acenes such as pentacene (five rings) or tetracene (four rings), positioning it as a potential low-bandgap semiconductor.<ref>{{cite journal |last1=Zuzak |first1=Rafal |last2=Dorel |first2=Ruth |last3=Krawiec |first3=Mariusz |last4=Such |first4=Bartosz |last5=Kolmer |first5=Marek |last6=Szymonski |first6=Marek |last7=Echavarren |first7=Antonio M. |last8=Godlewski |first8=Szymon |title=Nonacene Generated by On-Surface Dehydrogenation |journal=ACS Nano |date=26 September 2017 |volume=11 |issue=9 |pages=9321–9329 |doi=10.1021/acsnano.7b04728 |pmid=28817255 |bibcode=2017ACSNa..11.9321Z |url=https://iciq.org/new/nonacene-joins-the-acenes-family/}}</ref>
==Synthesis== In 2010, the Bettinger group reported a photochemical synthesis of octacene and nonacene, utilizing a cryogenic matrix-isolation technique to stabilize these highly reactive acenes. This approach requires precursors containing a double ''α''-diketone bridge to enable the formation of octacene and nonacene.<ref>{{cite journal |last1=Lerena |first1=Laura |last2=Zuzak |first2=Rafal |last3=Godlewski |first3=Szymon |last4=Echavarren |first4=Antonio M. |title=The Journey for the Synthesis of Large Acenes |journal=Chemistry – A European Journal |date=2024 |volume=30 |issue=57 |article-number=e202402122 |doi=10.1002/chem.202402122 |pmid=39077888 |bibcode=2024ChEuJ..30E2122L |language=en |issn=1521-3765|doi-access=free }}</ref><ref>{{cite journal |last1=Kaur |first1=Irvinder |last2=Jazdzyk |first2=Mikael |last3=Stein |first3=Nathan N. |last4=Prusevich |first4=Polina |last5=Miller |first5=Glen P. |title=Design, Synthesis, and Characterization of a Persistent Nonacene Derivative |journal=Journal of the American Chemical Society |date=3 February 2010 |volume=132 |issue=4 |pages=1261–1263 |doi=10.1021/ja9095472 |pmid=20055388 |bibcode=2010JAChS.132.1261K |url=https://pubs.acs.org/doi/10.1021/ja9095472 |access-date=30 March 2026|url-access=subscription }}</ref>
==Uses== Nonacene is of significant interest in organic electronics due to its exceptional semiconductor properties, though its high chemical reactivity and instability have historically made it one of the most challenging acenes to synthesize and isolate.<ref>{{cite web |title=Preparative-scale synthesis of nonacene – CEMES |url=https://www.cemes.fr/en/preparative-scale-synthesis-of-nonacene/ |publisher=cemes.fr |access-date=30 March 2026}}</ref><ref>{{cite web |title=UNH chemists create molecule with promising semiconductor properties |url=https://www.chemeurope.com/en/news/113424/unh-chemists-create-molecule-with-promising-semiconductor-properties.html |publisher=chemeurope.com |access-date=30 March 2026 |language=en}}</ref>
==References== {{Reflist}}
{{Hydrocarbons}} {{PAHs}}
Category:Acenes Category:Polycyclic aromatic hydrocarbons Category:Substances discovered in the 2010s Category:Semiconductors