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. This compound has long been pursued by chemists because of its potential interest in electronic applications and was first synthesized but not cleanly isolated in 2006. Heptacene was finally fully characterized in bulk by researchers in Germany and the United States in 2017.
:
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
dimer
Dimer may refer to:
* Dimer (chemistry), a chemical structure formed from two similar sub-units
** Protein dimer, a protein quaternary structure
** d-dimer
* Dimer model, an item in statistical mechanics, based on ''domino tiling''
* Julius Dimer ( ...
s. When on the other hand the dione precursor is dissolved in a
PMMA PMMA may refer to:
* para-Methoxymethamphetamine, a stimulant drug
* Philippine Merchant Marine Academy
The Philippine Merchant Marine Academy ( fil, Akademiya sa Bapor Pangkalakalan ng Pilipinas) also referred to by its acronym PMMA) is a ma ...
matrix first, heptacene can be studied by spectroscopy. Heptacene has been studied spectroscopically at cryogenic temperatures in a
matrix
Matrix most commonly refers to:
* ''The Matrix'' (franchise), an American media franchise
** ''The Matrix'', a 1999 science-fiction action film
** "The Matrix", a fictional setting, a virtual reality environment, within ''The Matrix'' (franchis ...
. When dissolved in
sulfuric acid
Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular formu ...
the heptacene dication is reported to be stable at room-temperature for more than a year in absence of oxygen.
"
solatedsolid heptacene has a half-life time of several weeks at room temperature."
Derivatives
:
:
7,16-Bis(tris(trimethylsilyl)silylethynyl)heptacene was synthesized in 2005. 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) and with phenyl and triisopropylsilylethynyl groups (Figure 2).
References
{{PAHs
Acenes
Polycyclic aromatic hydrocarbons
Substances discovered in the 2000s