Nuno A. G. Bandeira, principal investigator from the Chemistry for Biological Systems Group, published a new research article in the scientific journal Inorganic Chemistry Frontiers, from the Royal Society of Chemistry, on which he describes  the structure and properties of four new cobalt (II) complexes presenting single-ion magnet behavior. 

These compounds behave like a binary switching at the atomic scale and, due to their propoerties, can ultimately revolutionise the industry of all electronic devices from desktop PCs to smartphones. Find out in detail this finding by reading the BioISIDigest below.


What was the starting point that led to the current research?

Since the advent of the discovery of single-molecule magnets there has been the need to map out a course to improve and optimize their performance. The smallest scale at which this can be achieved is the atomic scale and the smallest single molecule magnet that can be created holds a single metal ion. Tetrahedral cobalt complexes in this case have been relatively unexplored. Previously the synthesist group, composed by Patricia Ferreira, Tiago Filipe Cruz e Pedro Teixeira Gomes, co-authors of this paper, had published a set of cobalt complexes with a view to applying them for catalysis, but surprisingly they turned out to have good uniaxial anisotropy which meant that thermally they can oscillate between different magnetic moments, like a quantum compass. This was our starting point, to re-examine those physical properties and see how we can fine tune the ligand field to improve them.

What is the main finding reported in this paper?

We’ve discovered four cobalt(II) molecules that show very high magnetic anisotropy. They are not the highest thus far but they are certainly among the highest. In addition, we show through computational chemistry methods which structural distortions on the ligand field are required to boost these magnetic properties.

Why is it important for the scientific community and for society at large?

There are currently two ‘battle fronts’ with regards to research of single molecule magnets: one of them handles research with lanthanide complexes. And indeed, one may obtain gigantic magnetisation reversal barriers from them. But lanthanides are costly to produce. The other research front handles first row transition metals which are cheaper to obtain but the magnetisation barriers are much smaller which means they can only function adequately at very low temperatures. Ideally one would like to attempt to obtain a single molecule magnet that operates at room temperature (2.5 kJ mol-1 or 200 cm-1). Having a binary switching at the atomic scale is the ultimate goal of quantum computing. This would revolutionise the industry of all electronic devices from desktop PCs to smartphones.

What are the next steps?

We intend to go on surveying this largely unexplored field of cobalt(II) complexes. My particular contribution in general is to give experimentalists the design principles they need to design the ideal ligands for an optimum single molecule magnet. Also the underlying physico-chemical basis of these properties are needed to adequately understand and to improve single molecule magnets. It is this feedback loop that allows for a productive and rewarding collaboration between chemists with widely different backgrounds.

Discover more about Nuno A. G. Bandeira’s research here.

Get to know the Chemistry for Biology Systems Group here.

Read the paper’s abstract here.

Nuno A. G. Bandeira [photo provided by the researcher].