Hypervalent molecule

As hypervalency [ Greek: hyper: over too much, see list of Greek prefixes ] is the positive deviation from the Valenzstrukturtheorie called, after which the outer shell of an atom more than that can accommodate after the noble gas configuration of s -and p- orbitals possible eight electrons ( octet rule ). It occurs in compounds of heavy main group elements of the 3rd to 8th main group with strong electron acceptors such as oxygen or fluorine. For example in Selenhalogeniden as selenium hexafluoride ( SeF6 ) or Iodfluoriden (e.g., IF5, IF7 ), generally in many inert gas, and interhalogen compounds. Until recently, here is a participation of the d orbitals of the central atom was adopted, but a description is now preferred by an electron-rich multicenter bonding.

Examples

Hypervalent iodine compounds

In synthetic organic chemistry hypervalent iodine compounds are widely used as a mild oxidant. These "modern" oxidizing agents include, and Others:

Dess- Martin periodinane is especially used in the so-called Dess-Martin oxidation. Furthermore, there are hypervalent iodine reagents, which are used ( attack of I to nucleophilic substrates, eg carbon-carbon double bonds) to the electrophilic introduction of iodine: