Models contend iodine double bonds


I-O bonds within the periodate ion are usually represented as double bonds (left), but AdNDP suggests they are dative (right) © Wiley-VCH

Hypervalent iodine reagents are widely used in organic synthesis, but their structures haven’t been studied in detail. In the majority of textbooks and papers, they are drawn with double bonds between iodine and oxygen, nitrogen or carbon.

But a new study has used theoretical models to show that this might be incorrect. Instead, it suggests the bonds within some of these compounds are dative, with iodine donating the electron pair.

A team led by Alexander Boldyrev and Viktor Zhdankin at Utah State University in the US examined the nature of the bonds within compounds such as iodosylbenzene (PhIO) and the periodate ion (IO4-) using a bond modelling technique called adaptive natural density partitioning (AdNDP). Their calculations revealed the bonds to be dative rather than double.

The group says the discovery will be useful when it comes to understanding reaction mechanisms, and suggests the textbooks may need correcting.

References

A S Ivanov et al, Angew. Chem. Int. Ed., 2014, DOI: 10.1002/anie.201405142


Related Content

What is a bond?

30 January 2014 Premium contentFeature

news image

There’s more to bonding than covalent, ionic and the lines we draw between atoms on paper. Philip Ball takes on the expandi...

What we mean when we talk about bonds

29 January 2015 Comments

news image

Santiago Alvarez delves into the debates and disagreements that surround one of chemistry's most fundamental concepts

Most Read

First pictures of hydrogen bonds unveiled

26 September 2013 Research

news image

Observation of intermolecular interactions in quinolines could help to settle the nature of this kind of bonding

Flowing rivers of mercury

7 January 2015 Feature

news image

Philip Ball investigates claims that the burial chamber of China’s first emperor contains rivers of shimmering mercury

Most Commented

SiRNA treatment cures Ebola in monkeys

23 April 2015 Research

news image

Researchers perform the first successful trial for a drug against the current strain of Ebola

Relativity behind mercury's liquidity

21 June 2013 Research

news image

First evidence that relativistic effects are indeed responsible for mercury's low melting point