Scientists have created an iron-based ring structure that could be used for new applications in electronics and sensing, an advance which may lead to better computers, catalysts and other nanomaterials.
Ferrocene is a molecule that was discovered in the 1950s. It is made up of two rings of hydrogen and carbon bound either side of an iron atom, researchers said.
This and other 'sandwich compounds' have unique properties that have led to their widespread use as industrial catalysts, pharmaceuticals and fuel additives, they said.
Now, researchers from Imperial College London in the UK and University of Konstanz in Germany have created a series of rings containing ferrocene molecules directly linked together for the first time - forming a molecular 'daisy chain'.
The cyclic structures have unique electrical properties that could be used in new electronics and sensing devices.
When researchers studied the way electrical charge is handled by the rings, they found that interactions between individual ferrocene units resulted in an unusual charging behaviour of the entire ring.
Adjusting the charge on one ferrocene unit causes the other units in the ring to re-arrange their charges without actually transferring the charge itself. This would avoid heating the molecules as the charge passes through, as happens with conventional electronics, researchers said.
This is similar to the way some small metal nanoparticles behave. The properties of these nanoparticles mean they are being investigated for use as 'molecular switches' in new types of computing, they said.
However, the use of nanoparticles is limited as it is difficult to produce particles with exactly the same shape and size, and hence the same properties, researchers said.
"We see applications of these ferrocene ring systems in memory or switching devices. When we manufacture ferrocene rings they are all identical, as opposed to some existing nanomaterials," said Nicholas Long and Tim Albrecht from Imperial College.
"This would make them much better candidates for molecular switches in computing, as the way they react to different charges would be exactly the same each time," they said.
Researchers originally set out to create a 'molecular square', a compound containing four ferrocene units (one ferrocene at each corner), but discovered that their process had actually created a ring containing six units.
They later developed methods to prepare rings containing between two and nine ferrocene units.
Researchers will now continue to study the electrical properties of the ring structures and how they might be used in computers, catalysts and other nanomaterials.
The findings were published in the journal Nature Chemistry.
