02-Aug-2017 - Universitat de Barcelona

New algorithm finds the optimal bond breaking point for single molecules

Recent developments in atomic-force microscopy have enabled researchers to apply mechanical forces to individual molecules to induce chemical reactions.

A research team from Spain and Germany has now developed a first-of-its-kind algorithm that determines the minimal force it takes to reach the optimal bond breaking point (BBP) at the molecular level to mechanically induce a chemical reaction.

The algorithm can be applied to any molecule, including biological molecules like proteins as well as inorganic molecules. Their research has implications for numerous applications, including molecular machines, mechanically resilient and self-healing polymers, stress-responsive materials and catalyst design. The algorithm can also be used to explore how external electric fields can catalyze and control chemical reactions.

When studying mechano-chemical processes, researchers look for the mechanical response of the reactant molecule's minimum-energy structure. As the external force increases, the minimum energy and transition state structures on the force-modified potential energy surface become identical and the structure where this occurs is the sought-after BBP.

"Our work highlights that there exists another set of important points on the potential energy surface of a given system, namely the BBP, which needs to be taken into consideration for mechano-chemistry applications," said Wolfgang Quapp, a co-author of the paper who added that BBP is a new concept in mechano-chemistry.

The optimal BBPs of a potential energy surface are crucial, according to Quapp, because they provide information about the way in which tensile forces should be applied to trigger chemical transformations with the highest possible efficiency using the least amount of force.

The bond, bending and torsion of a molecule have varying stiffness. Therefore, determining the force-bearing scaffold of a molecule, to predict, for example, the point of bond rupture in an overstretched molecule, means that different directions of the external force should be tested.

"Our algorithm allows researchers to identify which part of a molecule is most susceptible to mechanical stress, and thus the algorithm is a significant step in the design of more efficient ways of harnessing mechanical energy to activate chemical reactions," Quapp said. "The importance of the optimal BBP resides in that it gives the optimal direction and magnitude of the pulling force. This necessitates an algorithm to easily find these types of points."

The algorithm is based on Newton trajectories, which come from the mathematical method of calculating zeros of a function. In the case of BBPs, the Newton trajectories are located near the reaction path of the chemical reaction under consideration.

Facts, background information, dossiers
  • transition states
  • stiffness
  • Rearrangement
More about Universitat de Barcelona
  • News

    New mechanism to transfer chirality between molecules in the nanoscale field

    If we compare the right to the left hand, we can see these are specular images —that is, like symmetrical shapes reflected in a mirror— and they cannot superimpose on each other. This property is chirality, a feature of the matter that plays with the symmetry of biological structures at dif ... more

    How to cool more efficiently

    In the journal Applied Physics Reviews, an international research team from the University of Barcelona, the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), and TU Darmstadt report on possibilities for implementing more efficient and environmentally friendly refrigeration processes. For this p ... more

    A study describes liquid water diffusion at molecular level

    An article published in Physical Review and conducted by researchers at the universities of Granada and Barcelona might lead to a revolutionary change in water desalination and filtration methods. Researchers at the universities of Granada and Barcelona have described for the first time the ... more

More about Uni Leipzig
More about American Institute of Physics
  • News

    Solar cell keeps working long after sun sets

    About 750 million people in the world do not have access to electricity at night. Solar cells provide power during the day, but saving energy for later use requires substantial battery storage. In Applied Physics Letters, by AIP Publishing, researchers from Stanford University constructed a ... more

    Turning plastic grocery bags into sustainable fuel

    More than 300 million tons of plastic waste are produced annually, which causes serious environmental issues because of plastic's life cycle and the difficulty of eliminating it. Consequently, most plastic waste ends up in either a landfill or the ocean. A significant number of plastics bre ... more

    Turning hazelnut shells into potential renewable energy source

    Biomass is attracting growing interest from researchers as a source of renewable, sustainable, and clean energy. It can be converted into bio-oil by thermochemical methods, such as gasification, liquefaction, and pyrolysis, and used to produce fuels, chemicals, and biomaterials. In Journal ... more