Definition of Halonium. Meaning of Halonium. Synonyms of Halonium

- A halonium ion is any onium ion containing a halogen atom carrying a positive charge. This cation has the general structure R−+X−R′ where X is any halogen...
- stabilize the carbocation by donating electrons at the expense of the halonium ion. Halonium ions can be identified by means of NMR spectroscopy. In 1967 the...
- In chemistry, an onium ion is a cation formally obtained by the protonation of mononuclear parent hydride of a pnictogen (group 15 of the periodic table)...
- loss of aromaticity, which has a higher activation energy compared to halonium ion formation in alkenes. In other words, alkenes are more reactive and...
- from the nucleophilic abstraction reaction. An iminium ion reacts with a halonium ion formed in situ by reaction of an alkene with iodine. Lactams form by...
- electrophilic addition to the alkene group with electrophiles such as halonium ions, Brønsted acids and Lewis acids. In type 3 the substrates are epoxides...
- + 2 H2O The addition of halogens to alkenes proceeds via intermediate halonium ions. In special cases, such intermediates have been isolated. Bromination...
- to the heavier halogens, which have long been known to form open-chain halonium ions (such as [Me2Cl]+[Al(OTeF5)4]–) as well as cyclic haliranium ions...
- cyclohexene derivatives. Cyclohexene derivatives, such as imines, epoxides, and halonium ions, react with nucleophiles in a stereoselective fashion, affording trans-diaxial...
- dinitrogen. Stable carbenes also have a ylidic resonance contributor, e.g.: Halonium ylides can be prepared from allyl halides and metal carbenoids. After a...