In the beginning…: The Nobel Prize in Chemistry 2016 goes to three of the pioneers of the field of synthetic molecular machines, Jean‐Pierre Sauvage, Sir J. Fraser Stoddart, and Ben L. Feringa. Their ...work has led from the reliable synthesis of rotaxanes and catenanes (see picture) to molecular rotary motors, shuttles, muscles, and other devices.
Artificial switchable catalysts Blanco, Victor; Leigh, David A; Marcos, Vanesa
Chemical Society reviews,
08/2015, Letnik:
44, Številka:
15
Journal Article
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Catalysis is key to the effective and efficient transformation of readily available building blocks into high value functional molecules and materials. For many years research in this field has ...largely focussed on the invention of new catalysts and the optimization of their performance to achieve high conversions and/or selectivities. However, inspired by Nature, chemists are beginning to turn their attention to the development of catalysts whose activity in different chemical processes can be switched by an external stimulus. Potential applications include using the states of multiple switchable catalysts to control sequences of transformations, producing different products from a pool of building blocks according to the order and type of stimuli applied. Here we outline the state-of-art in artificial switchable catalysis, classifying systems according to the trigger used to achieve control over the catalytic activity and stereochemical or other structural outcomes of the reaction.
Molecular machines with bio-inspired mechanisms Zhang, Liang; Marcos, Vanesa; Leigh, David A.
Proceedings of the National Academy of Sciences - PNAS,
09/2018, Letnik:
115, Številka:
38
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The widespread use of molecular-level motion in key natural processes suggests that great rewards could come from bridging the gap between the present generation of synthetic molecular machines—which ...by and large function as switches—and the machines of the macroscopic world, which utilize the synchronized behavior of integrated components to perform more sophisticated tasks than is possible with any individual switch. Should we try to make molecular machines of greater complexity by trying to mimic machines from the macroscopic world or instead apply unfamiliar (and no doubt have to discover or invent currently unknown) mechanisms utilized by biological machines? Here we try to answer that question by exploring some of the advances made to date using bio-inspired machine mechanisms.
3D printing technology can produce complex objects directly from computer aided digital designs. The technology has traditionally been used by large companies to produce fit and form concept ...prototypes ('rapid prototyping') before production. In recent years however there has been a move to adopt the technology as full-scale manufacturing solution. The advent of low-cost, desktop 3D printers such as the RepRap and Fab@Home has meant a wider user base are now able to have access to desktop manufacturing platforms enabling them to produce highly customised products for personal use and sale. This uptake in usage has been coupled with a demand for printing technology and materials able to print functional elements such as electronic sensors. Here we present formulation of a simple conductive thermoplastic composite we term 'carbomorph' and demonstrate how it can be used in an unmodified low-cost 3D printer to print electronic sensors able to sense mechanical flexing and capacitance changes. We show how this capability can be used to produce custom sensing devices and user interface devices along with printed objects with embedded sensing capability. This advance in low-cost 3D printing with offer a new paradigm in the 3D printing field with printed sensors and electronics embedded inside 3D printed objects in a single build process without requiring complex or expensive materials incorporating additives such as carbon nanotubes.
The widespread use of controlled molecular‐level motion in key natural processes suggests that great rewards could come from bridging the gap between the present generation of synthetic molecular ...systems, which by and large rely upon electronic and chemical effects to carry out their functions, and the machines of the macroscopic world, which utilize the synchronized movements of smaller parts to perform specific tasks. This is a scientific area of great contemporary interest and extraordinary recent growth, yet the notion of molecular‐level machines dates back to a time when the ideas surrounding the statistical nature of matter and the laws of thermodynamics were first being formulated. Here we outline the exciting successes in taming molecular‐level movement thus far, the underlying principles that all experimental designs must follow, and the early progress made towards utilizing synthetic molecular structures to perform tasks using mechanical motion. We also highlight some of the issues and challenges that still need to be overcome.
Exercising demons: Although the notion of synthetic molecular‐level motors and machines has been around for 150 years (for example, Maxwell's demon, see picture), it is only recently that research in this area has flourished. The current state of the art in regard to how the components of molecular‐level structures can be switched, rotated, speeded up, slowed down, and directionally driven in response to stimuli is described in the Review.
Catenanes: Fifty Years of Molecular Links Gil-Ramírez, Guzmán; Leigh, David A.; Stephens, Alexander J.
Angewandte Chemie (International ed.),
May 18, 2015, Letnik:
54, Številka:
21
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Half a century after Schill and Lüttringhaus carried out the first directed synthesis of a 2catenane, a plethora of strategies now exist for the construction of molecular Hopf links (singly ...interlocked rings), the simplest type of catenane. The precision and effectiveness with which suitable templates and/or noncovalent interactions can arrange building blocks has also enabled the synthesis of intricate and often beautiful higher order interlocked systems, including Solomon links, Borromean rings, and a Star of David catenane. This Review outlines the diverse strategies that exist for synthesizing catenanes in the 21st century and examines their emerging applications and the challenges that still exist for the synthesis of more complex topologies.
Half a century after Schill and Lüttringhaus carried out the first directed synthesis of a 2catenane, a plethora of strategies now exist for the construction of interlocked molecular rings. Effective template synthesis enables the synthesis of higher order interlocked systems. This Review outlines the diverse strategies that exist for forming catenanes, their applications, and the important challenges that remain in the field of chemical topology.
Molecular Knots Fielden, Stephen D. P.; Leigh, David A.; Woltering, Steffen L.
Angewandte Chemie (International ed.),
September 4, 2017, Letnik:
56, Številka:
37
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The first synthetic molecular trefoil knot was prepared in the late 1980s. However, it is only in the last few years that more complex small‐molecule knot topologies have been realized through ...chemical synthesis. The steric restrictions imposed on molecular strands by knotting can impart significant physical and chemical properties, including chirality, strong and selective ion binding, and catalytic activity. As the number and complexity of accessible molecular knot topologies increases, it will become increasingly useful for chemists to adopt the knot terminology employed by other disciplines. Here we give an overview of synthetic strategies towards molecular knots and outline the principles of knot, braid, and tangle theory appropriate to chemistry and molecular structure.
Thou shalt knot … This Review gives an overview of the field of closed‐loop molecular entanglements in terms of their synthesis, and outlines the principles of knot, braid, and tangle theory appropriate to chemistry and molecular structure. The steric restrictions imposed on molecular strands by knotting can impart significant physical and chemical properties, including chirality, strong and selective ion binding, and catalytic activity.
Rise of the Molecular Machines Kay, Euan R.; Leigh, David A.
Angewandte Chemie (International ed.),
August 24, 2015, Letnik:
54, Številka:
35
Journal Article
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They’re coming! From Feynman to ribosome mimics, the evolution of artificial molecular machines is told in terms of key inventions and the questions the field continues to face, including design ...philosophies and what to make and why.
Many biomolecular motors catalyze the hydrolysis of chemical fuels, such as adenosine triphosphate, and use the energy released to direct motion through information ratchet mechanisms. Here we ...describe chemically-driven artificial rotary and linear molecular motors that operate through a fundamentally different type of mechanism. The directional rotation of 2- and 3catenane rotary molecular motors and the transport of substrates away from equilibrium by a linear molecular pump are induced by acid-base oscillations. The changes simultaneously switch the binding site affinities and the labilities of barriers on the track, creating an energy ratchet. The linear and rotary molecular motors are driven by aliquots of a chemical fuel, trichloroacetic acid. A single fuel pulse generates 360° unidirectional rotation of up to 87% of crown ethers in a 2catenane rotary motor.
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