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...

First snapshot of elusive intermediate supplies surprise

13 July 2015 Research

news image

Atomic force microscopy images reveal aryne possesses three consecutive carbon–carbon double bonds, rather than a single tr...

Most Read

Flushing advice is flawed

24 August 2015 Research

news image

Protocols to restore contaminated water supplies are not based on science

Simple chemistry saving thousands of gold miners from mercury poisoning

25 August 2015 News and Analysis

news image

Basic apparatus is cutting mercury pollution and helping Indonesian miners go for gold

Most Commented

New drug treatment for alcoholism shows promise in animal studies

24 August 2015 Research

news image

Compounds that target a receptor in the brain appear less addictive with fewer negative side-effects than existing drugs

A risky business

28 August 2015 In the Pipeline

news image

Graduate research is likely the most risky time of a chemist’s career, says Derek Lowe