Ricerc@Sapienza

This work aimed to render phenomenologically autonomous the otherwise stepwise operation of a catenane-based molecular switch, which is chemically triggered by the decarboxylation of 2-cyano-2-phenylpropanoic acid (2). Given that any amount of 2 in stoichiometric excess with respect to the catenane is consumed in a side reaction, the authors resorted to the corresponding anhydride 5, the slow hydrolysis of which, due to adventitious water in dichloromethane, continuously produces in situ the actual fuel 2.

Natural molecular machines require a continuous fuel supply to perform motions and/or remain in a functional state. Consequently, the aim of developing artificial devices and materials with life-type properties has motivated a growing interest in abiotic chemical fuels and in their supply modalities. Many artificial molecular machines have been developed in which the sequential addition of several chemical reagents allows the machine to perform complete cycles of motion.