A closer look at the motion of p-carborane on gold surface

In recent years, nanocars with p-carborane wheels have been a subject of interest as an artificial molecular machine. Researchers aim to discover compositions that are easier to fabricate, efficient and are more stable on the surface. The p-carborane molecule has all these key elements, making it a viable choice as a nanocar wheel, and the mobility of a nanocar is heavily influenced by the motion of its wheels. In this research, we use classical Molecular Dynamics (MD) in isothermal conditions to specify the regime of motion of p-carborane at different temperatures. We find that by raising the temperature, three different regimes of motion may be observed: jumps to adjacent cells, long jumps, and continuous motion. The MD results demonstrate that rotation around a horizontal axis is harder than pure sliding while rotation around a vertical axis is easier and likely to occur even at low temperatures. The results of this study not only provide quantitative criteria for specifying the regime of motion of p-carborane on the gold surface, but can also be used to estimate the behavior of thermally-driven or motorized carborane-based nanocars and their motion on similar substrates.