Electrostatic catalysis of a Diels-Alder reaction
MetadataShow full item record
It is often thought that the ability to control reaction rates with an applied electrical potential gradient is unique to redox systems. However, recent theoretical studies suggest that oriented electric fields could affect the outcomes of a range of chemical reactions, regardless of whether a redox system is involved. This possibility arises because many formally covalent species can be stabilized via minor charge-separated resonance contributors. When an applied electric field is aligned in such a way as to electrostatically stabilize one of these minor forms, the degree of resonance increases, resulting in the overall stabilization of the molecule or transition state. This means that it should be possible to manipulate the kinetics and thermodynamics of non-redox processes using an external electric field, as long as the orientation of the approaching reactants with respect to the field stimulus can be controlled. Here, we provide experimental evidence that the formation of carbon-carbon bonds is accelerated by an electric field. We have designed a surface model system to probe the Diels-Alder reaction, and coupled it with a scanning tunnelling microscopy break-junction approach. This technique, performed at the single-molecule level, is perfectly suited to deliver an electric-field stimulus across approaching reactants. We find a fivefold increase in the frequency of formation of single-molecule junctions, resulting from the reaction that occurs when the electric field is present and aligned so as to favour electron flow from the dienophile to the diene. Our results are qualitatively consistent with those predicted by quantum-chemical calculations in a theoretical model of this system, and herald a new approach to chemical catalysis.
Showing items related by title, author, creator and subject.
Formation and characteristics of glucose oligomers during the hydrolysis of cellulose in hot-compressed waterYu, Yun (2009)Energy production from fossil fuels results in significant carbon dioxide emission, which is a key contributor to global warming and the problems related to climate change. Biomass is recognized as an important part of ...
Development and application of processing techniques for signal enhancement using multisystem resistivity measurementsKamkar-Rouhani, Abolghasem (1998)DC electrical surveying involves the injection of current into the earth, and the measurement of the electrical potential differences this produces. A number of electrode configurations such as the Schlumberger and Wenner ...
Lumentut, Mikail; Friswell, M. (2018)© 2018, Springer-Verlag GmbH Austria, part of Springer Nature. This paper presents an electromechanical dynamic modelling of the partially smart pipe structure subject to the vibration responses from fluid flow and input ...