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The compound is the prototypical antiaromatic hydrocarbon with 4 pi electrons (or π electrons). It is the smallest [n]-annulene ([4]-annulene).Its rectangular structure is the result of a pseudo [3] - (or second order) Jahn–Teller effect, which distorts the molecule and lowers its symmetry, converting the triplet to a singlet ground state. [4]
For example, the aromatic species 1 can be reduced to 2 with a relatively small penalty for forming an antiaromatic system. The antiaromatic 2 does revert to the aromatic species 1 over time by reacting with oxygen in the air because the aromaticity is preferred. [15] The loss of antiaromaticity can sometimes be the driving force of a reaction.
Rust converters are chemical solutions or primers that can be applied directly to an iron or iron alloy surface to convert iron oxides into a protective chemical barrier. These compounds interact with iron oxides, especially iron(III) oxide , converting them into an adherent black layer ( black oxide ) that is more resistant to moisture and ...
Unlike most acid-based rust removers, POR-15–short for Paint Over Rust–not only melts away rust, but preps the metal underneath for paint by lightly etching the metal and leaving behind a zinc ...
In organic chemistry, a cycloalkene or cycloolefin is a type of alkene hydrocarbon which contains a closed ring of carbon atoms and either one or more double bonds, but has no aromatic character. Some cycloalkenes, such as cyclobutene and cyclopentene , can be used as monomers to produce polymer chains. [ 1 ]
Petroleum-based rust-inhibitors provide several benefits, including the ability to creep over metal, covering missed areas. [citation needed] Additionally, a petroleum, solvent-free rust inhibitor remains on the metal surface, sealing it from rust-accelerating water and oxygen. Other benefits of petroleum-based rust protection include the self ...
This reaction is based on a ring expansion of the cyclopropanone intermediate initially formed, wherein molecular nitrogen is split off: The reaction mechanism was confirmed by a reaction using 14 C-labeled diazomethane.
Benzocyclobutene is a strained system which, upon heating to approximately 180 °C, causes the cyclobutene to undergo a conrotatory ring-opening reaction, forming o-xylylene. Since this process destroys the aromaticity of the benzene ring, the reverse reaction is highly favored. Thermal generation of o-xylylene from benzocyclobutene