A team of researchers, led by UVM assistant professor of chemistry Severin Schneebeli, has discovered a way to create a nanoscale wrench that can be used to adjust the shape of other molecules. Similar to how a mechanic uses a wrench to adjust a bolt, these nanoscale wrenches can be used to adjust the chemical environment inside other molecules and change the molecule’s symmetry with precision. These newly formed molecules could then be combined to form novel synthetic materials “with properties that, today, no material has.”
The nanowrench is formed using the principles of chirality, in which a molecule has two identical but opposite forms, similar to a human’s left and right hand. Because they are chiral, these molecules can be joined together in one orientation, much like Lego pieces that fit together in a specific way. This one directional joining means the structure can only take one shape and does not twist or rotate into different shapes. “It completely keeps its shape, even in various solvents and at many different temperatures,” explains Schneebeli. This property “makes it pre-organized to bind to other molecules in one specific way.”
The UVM team found that the C-shaped nanowrench binds reliably to “pillarene macrocycles,” a large class of molecules that show promise in controlled drug delivery experiments and other applications. The team was able to manipulate the pillarene rings inside the macrocycles and make the binding inside the rings a hundred times stronger. Schneebeli used computer modeling to predict the action of the wrench and the subsequent rigid binding of molecules, allowing them to know what will happen to the system before synthesizing it in the lab. Following simulation studies, Schneebeli and his team used a mass spectrometer and an NMR spectrometer to confirm the model’s predictions.
After publishing their results online in chemistry journal Angewandte Chemie, the team hopes to modify its C-shaped nanowrenches and create a helical wrench that will be flexible like a spring and still hold its shape under stress. This helical wrench and other future shapes could be used to create even more new materials, some of which may have ground-breaking properties.