Molecular motor running on electricity mimics biological motors

A molecular motor that can be powered by electricity has been created.¹ In contrast to existing single-molecule electric motors,^2,3 the new ³catenane motor can be operated without a scanning tunnelling microscopy tip. ‘Previous electrically driven motors required high vacuum and elaborated setups to operate,’ comments Giulio Ragazzon from the University of Strasbourg in France, who wasn’t involved in the study. ‘The present system works under mild conditions – an important requirement for further progress.’

‘Our catenane is composed of two small, identical, four positively charged rings and a much larger [50-membered] cyclic loop,’ says Long Zhang at Northwestern University in the US. ‘There are two different states – an oxidised and a reduced state – and by varying the voltage, we can achieve unidirectional, clockwise motion of the two rings around the loop.’ Ragazzon points out that one-way rotation wouldn’t happen spontaneously in this system. ‘Studies like this one are formidable advancements in the ability to control matter at the molecular level,’ he says.