Heptacene

In today's world, Heptacene has become a topic of great interest and relevance. Whether it is its impact on society, its influence on popular culture, or its importance in academia, Heptacene is a topic that captures the attention of a wide variety of audiences. In this article, we will explore the different facets of Heptacene, analyzing its importance, its history and its relevance in today's world. From its origins to its evolution in the present, Heptacene has left an indelible mark on our lives and deserves to be studied and understood in all its complexity. Through detailed analysis, we hope to shed light on this topic and give our readers a broader and deeper insight into Heptacene.

Heptacene
Skeletal formula of heptacene
Skeletal formula of heptacene
Space-filling model of the heptacene molecule
Names
Preferred IUPAC name
Heptacene
Identifiers
3D model (JSmol)
ChemSpider
UNII
  • InChI=1S/C30H18/c1-2-6-20-10-24-14-28-18-30-16-26-12-22-8-4-3-7-21(22)11-25(26)15-29(30)17-27(28)13-23(24)9-19(20)5-1/h1-18H
  • c1cc2cc3cc4cc5cc6cc7ccccc7cc6cc5cc4cc3cc2ccc1
Properties
C30H18
Molar mass 378.474 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa).

Heptacene is an organic compound and a polycyclic aromatic hydrocarbon and the seventh member of the acene or polyacene family of linear fused benzene rings.[1] This compound has long been pursued by chemists[2][3][4] because of its potential interest in electronic applications and was first synthesized but not cleanly isolated in 2006.[5][6] Heptacene was finally fully characterized in bulk by researchers in Germany and the United States in 2017.[7]

heptacene synthesis
heptacene synthesis

The final step is a photochemical decarbonylization with a 1,2-dione bridge extruded as carbon monoxide. In solution heptacene is not formed because it is very unstable being a reactive DA diene and quickly reacts with oxygen or forms dimers. When on the other hand the dione precursor is dissolved in a PMMA matrix first, heptacene can be studied by spectroscopy. Heptacene has been studied spectroscopically at cryogenic temperatures in a matrix.[8] When dissolved in sulfuric acid the heptacene dication is reported to be stable at room-temperature for more than a year in absence of oxygen.[9] " solid heptacene has a half-life time of several weeks at room temperature."[10]

Derivatives

Figure 1.
Figure 2.

7,16-Bis(tris(trimethylsilyl)silylethynyl)heptacene was synthesized in 2005.[11] This compound is stable in the solid state for a week but decomposes in contact with air. Its synthesis started from anthraquinone and naphthalene-2,3-dicarboxaldehyde. More stable substituted heptacenes have been reported: with stabilizing p-(t-butyl)thiophenyl substituents (Figure 1)[12] and with phenyl and triisopropylsilylethynyl groups (Figure 2).[13]

References

  1. ^ Zade, Sanjio S.; Bendikov, Michael (2010). "Heptacene and Beyond: the Longest Characterized Acenes". Angewandte Chemie International Edition. 49 (24): 4012–5. doi:10.1002/anie.200906002. PMID 20468014.
  2. ^ Clar, E. (1942). "Heptacen ein einfacher, "ultragrüner"︁ Kohlenwasserstoff (Aromatische Kohlenwasserstoffe, XXXV. Mitteil.)". Berichte der Deutschen Chemischen Gesellschaft (A and B Series). 75 (11): 1330–1338. doi:10.1002/cber.19420751114.
  3. ^ Bailey, William J.; Liao, Chien-Wei (1955). "Cyclic Dienes. XI. New Syntheses of Hexacene and Heptacene1,2". Journal of the American Chemical Society. 77 (4): 992–993. doi:10.1021/ja01609a055.
  4. ^ Boggiano, B.; Clar, E. (1957). "519. Four higher annellated pyrenes with acene character". Journal of the Chemical Society (Resumed): 2681. doi:10.1039/JR9570002681.
  5. ^ Mondal, Rajib; Shah, Bipin K.; Neckers, Douglas C. (2006). "Photogeneration of Heptacene in a Polymer Matrix". Journal of the American Chemical Society. 128 (30): 9612–9613. doi:10.1021/ja063823i. PMID 16866498.
  6. ^ a| Diels-Alder reaction of dibromonaphthalene forming a naphthyne and bicyclooct-2,3,5,6,7-pentaene with n-butyllithium in toluene 3 hours at -50 to -60 °C 53% chemical yield b| organic oxidation with P-chloranil in toluene 2 hours reflux and 81% yield c] Bishydroxylation with N-Methylmorpholine N-oxide and osmium tetroxide in acetone and t-butanol at room temperature for 48 hours, 83% yield d] Swern oxidation with trifluoroacetic acid in dimethyl sulfoxide and dichloromethane at -78 °C, 51% yield e] photochemical decarbonylization in a PMMA matrix at 395 nm
  7. ^ Einholz, Ralf; Fang, Treliant; Berger, Robert; Grüninger, Peter; Früh, Andreas; Chassé, Thomas; Fink, Reinhold F.; Bettinger, Holger F. (2017). "Heptacene: Characterization in Solution, in the Solid State, and in Films". Journal of the American Chemical Society. 139 (12): 4435–4442. doi:10.1021/jacs.6b13212. PMID 28319405.
  8. ^ Mondal, Rajib; TöNshoff, Christina; Khon, Dmitriy; Neckers, Douglas C.; Bettinger, Holger F. (2009). "Synthesis, Stability, and Photochemistry of Pentacene, Hexacene, and Heptacene: A Matrix Isolation Study". Journal of the American Chemical Society. 131 (40): 14281–14289. doi:10.1021/ja901841c. PMID 19757812.
  9. ^ Einholz, R.; Bettinger, H. F. (2013). "Heptacene: Increased Persistence of a 4n+2 π-Electron Polycyclic Aromatic Hydrocarbon by Oxidation to the 4n π-Electron Dication". Angew. Chem. Int. Ed. 52: 9818–9820. doi:10.1002/anie.201209722. PMID 23873781.
  10. ^ Einholz, Ralf; Fang, Treliant; Berger, Robert; Grüninger, Peter; Früh, Andreas; Chassé, Thomas; Fink, Reinhold F.; Bettinger, Holger F. (2017). "Heptacene: Characterization in Solution, in the Solid State, and in Films". Journal of the American Chemical Society. 139 (12): 4435–4442. doi:10.1021/jacs.6b13212. PMID 28319405.
  11. ^ Payne, Marcia M.; Parkin, Sean R.; Anthony, John E. (2005). "Functionalized Higher Acenes: Hexacene and Heptacene". Journal of the American Chemical Society. 127 (22): 8028–9. doi:10.1021/ja051798v. PMID 15926823.
  12. ^ Kaur, Irvinder; Stein, Nathan N.; Kopreski, Ryan P.; Miller, Glen P. (2009). "Exploiting Substituent Effects for the Synthesis of a Photooxidatively Resistant Heptacene Derivative". Journal of the American Chemical Society. 131 (10): 3424–5. doi:10.1021/ja808881x. PMID 19243093.
  13. ^ Chun, Doris; Cheng, Yang; Wudl, Fred (2008). "The Most Stable and Fully Characterized Functionalized Heptacene". Angewandte Chemie International Edition. 47 (44): 8380–5. doi:10.1002/anie.200803345. PMID 18825763.