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The best Lewis structure for an oxocarbenium ion contains an oxygen–carbon double bond, with the oxygen atom attached to an additional group and consequently taking on a formal positive charge. In the language of canonical structures (or "resonance"), the polarization of the π bond is described by a secondary carbocationic resonance form ...
In chemistry, an oxocarbon anion is a negative ion consisting solely of carbon and oxygen atoms, and therefore having the general formula C x O n− y for some integers x, y, and n. The most common oxocarbon anions are carbonate, CO 2− 3, and oxalate, C 2 O 2− 4. There are however a large number of stable anions in this class, including ...
Another class of oxonium ions encountered in organic chemistry is the oxocarbenium ions, obtained by protonation or alkylation of a carbonyl group e.g. R−C= + −R′ which forms a resonance structure with the fully-fledged carbocation R− + −O−R′ and is therefore especially stable:
A carbenium ion is a positive ion with the structure RR′R″C +, that is, a chemical species with carbon atom having three covalent bonds, and it bears a +1 formal charge. Carbenium ions are a major subset of carbocations , which is a general term for diamagnetic carbon-based cations.
Two proposed mechanisms include a nucleophilic displacement and an oxocarbenium ion intermediate. [11] Example of an α-glucosidase catalyzed reaction: maltotriose + water → α-glucose. Rhodnius prolixus, a blood-sucking insect, forms hemozoin (Hz) during digestion of host hemoglobin. Hemozoin synthesis is dependent on the substrate binding ...
Brodie also discovered in 1859 a fifth compound called graphite oxide, consisting of carbon and oxygen in ratios varying between 2:1 and 3:1; but the nature and molecular structure of this substance remained unknown until a few years ago, when it was renamed graphene oxide and became a topic of research in nanotechnology.
The 2-norbornyl cation is one of the best characterized carbonium ion. It is the prototype for non-classical ions. As indicated first by low-temperature NMR spectroscopy and confirmed by X-ray crystallography, [1] it has a symmetric structure with an RCH 2 + group bonded to an alkene group, stabilized by a bicyclic structure.
(Right) Denmark's model system for acetal substitution mechanism. If the S N 1 mechanism is operative for the acetal substitution, the two reactions shown here should proceed via the same oxocarbenium ion and give similar stereochemical outcomes. Results indicate that the mechanism varies depending on the Lewis acid and the R group.