Utente:Grasso Luigi/sanbox1/Ione carbenio
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A carbenium ion is a positive ion with the structure RR′R″C+, that is, a chemical species with a trivalent carbon that bears a +1 formal charge.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/f/f1/Methyl_cation.svg/120px-Methyl_cation.svg.png)
In older literature the name carbonium ion was used for this class, but now it refers exclusively to another family of carbocations, the carbonium ions, where the charged carbon is pentavalent.[1] The current definitions were proposed by the chemist George Andrew Olah in 1972,[2] and are now widely accepted.
Carbenium ions are generally highly reactive due to having an incomplete octet of electrons; however, certain carbenium ions, such as the tropylium ion, are relatively stable due to the positive charge being delocalised between the carbon atoms.