Benzvalene is an

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. T ...

and one of several isomers of

benzene Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms ...

. It was first synthesized in 1971 by Thomas J. Katz et al. The 1971 synthesis consisted of treating cyclopentadiene with

methyllithium Methyllithium is the simplest organolithium reagent with the empirical formula CH3Li. This s-block organometallic compound adopts an oligomeric structure both in solution and in the solid state. This highly reactive compound, invariably used in so ...

dimethyl ether Dimethyl ether (DME; also known as methoxymethane) is the organic compound with the formula CH3OCH3, (sometimes ambiguously simplified to C2H6O as it is an isomer of ethanol). The simplest ether, it is a colorless gas that is a useful precursor ...

and then with dichloromethane and methyllithium in

diethyl ether Diethyl ether, or simply ether, is an organic compound in the ether class with the formula , sometimes abbreviated as (see Pseudoelement symbols). It is a colourless, highly volatile, sweet-smelling ("ethereal odour"), extremely flammable li ...

at −45 °C. It can also be formed in low yield (along with

fulvene Fulvene (pentafulvene) is a hydrocarbon with the formula (CH=CH)2C=CH2. It is a prototype of a cross-conjugated hydrocarbon. Fulvene is rarely encountered, but substituted derivatives (fulvenes) are numerous. They are mainly of interest as ligand ...

and

Dewar benzene Dewar benzene (also spelled ''dewarbenzene'') or bicyclo .2.0exa-2,5-diene is a bicyclic isomer of benzene with the molecular formula C6H6. The compound is named after James Dewar who included this structure in a list of possible C6H6 structures ...

) by irradiation of benzene at 237 to 254 nm. The hydrocarbon in solution was described as having an extremely foul odor. Due to the high

steric strain Van der Waals strain is strain resulting from Van der Waals repulsion when two substituents in a molecule approach each other with a distance less than the sum of their Van der Waals radii. Van der Waals strain is also called Van der Waals repul ...

present in benzvalene, the pure compound (~71 kcal/mol higher in energy than benzene) easily detonates, for example by scratching. The compound converts to benzene with a chemical half-life of approximately 10 days. This symmetry-forbidden transition is believed to take place through a

diradical In chemistry, a diradical is a molecular species with two electrons occupying molecular orbitals (MOs) which are degenerate. The term "diradical" is mainly used to describe organic compounds, where most diradicals are extremely reactive and i ...

intermediate.

Polybenzvalene

Benzvalene can be

polymerized In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are many for ...

in a

ROMP Romp or ROMP may refer to: * IBM ROMP The ROMP is a reduced instruction set computer (RISC) microprocessor designed by IBM in the late 1970s. It is also known as the Research OPD Miniprocessor (after the two IBM divisions that collaborated on i ...

process to polybenzvalene. This polymer contains highly strained

bicyclobutane Bicyclobutane is an organic compound with the formula C4H6. It is a bicyclic molecule consisting of two ''cis''-fused cyclopropane rings, and is a colorless and easily condensed gas. Bicyclobutane is noted for being one of the most strained co ...

rings which again makes it a sensitive material. The rings can be

isomerized In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. Is ...

to 1,3-dienes and for this reason polybenzvalene has been investigated as a precursor to

polyacetylene Polyacetylene (IUPAC name: polyethyne) usually refers to an organic polymer with the repeating unit . The name refers to its conceptual construction from polymerization of acetylene to give a chain with repeating olefin groups. This compound ...

References

External links

{{commonscatinline Explosive chemicals Cycloalkenes Tricyclic compounds Cyclopentenes Substances discovered in the 1970s