Molecules in Motion: Towards Hydrogen Bond-Assembled Molecular Machines

Abstract

Many phenomena of biological interest originate directly from mechanical motions at the molecular level. Celebrated examples include the trans-cis isomerisation of double bonds that triggers the visual signal and the rotary motion of the enzyme F₁-ATPase, the cornerstone of ADP to ATP conversion. This dependence on molecular level motion in key natural processes is inspiring scientists to try and bridge the gap between synthetic chemistry, which by and large relies upon electronic and chemical effects and does not exploit molecular motions, and the macroscopic world, where our everyday machines rely upon the synchronized motions of their components to perform their designated tasks. Accordingly, there is great current interest in trying to make molecular analogues of some of the fundamental components of machinery from the macroscopic world (cogs, wheels, shuttles, pistons etc) [1]. The idea is that such structures could form the basis of synthetic devices or materials that, like biological systems, could function through molecular level mechanical motion.