Light‐Driven Transport of a Molecular Walker in Either Direction along a Molecular Track

Barrell, Michael J.; Campaña, Araceli G.; Delius, Max von; Geertsema, Edzard M.; Leigh, David A.

doi:10.1002/ange.201004779

Cited by 62 publications

(24 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Machines need to be designed according to the environment they will function in 20,21 and the difference in the way matter behaves at different length scales means that a machine intended to mechanically transport a cargo between sites 2 nm apart cannot operate through the same mechanism as one that does so over 2 m. 7,20,21 Gravity is irrelevant at the molecular level and to stop the cargo exchanging with other cargo molecules in the bulk, or those associated with other platforms or robotic arms, the same cargo molecule must be bound to the machine ensemble at the start, throughout transport, and at the end. Dynamic covalent chemistry allows for such a process: [22][23][24] the cargo-platform linkage was chosen to be a hydrazone group able to exchange between aldehydes (the platform sites) under acid conditions but kinetically inert under basic conditions; the cargo-arm linkage was selected as a disulfide bond that is dynamic under basic conditions but locked under acidic conditions. Accordingly, at no time during the operation of the molecular machine can the cargo detach fully from both the platform and the robotic arm.…”

Section: Designmentioning

confidence: 99%

Pick-up, transport and release of a molecular cargo using a small-molecule robotic arm

et al. 2015

Self Cite

View full text Add to dashboard Cite

Modern day factory assembly lines often feature robots that pick up, reposition and connect components in a programmed manner. The idea of manipulating molecular fragments in a similar way has to date only been explored using biological building blocks (DNA). Here we report on a wholly artificial small-molecule robotic arm capable of selectively transporting a molecular cargo in either direction between two spatially distinct, chemically similar, sites on a molecular platform. The arm picks up/releases a 3-mercaptopropanehydrazide cargo by formation/breakage of a disulfide bond, while dynamic hydrazone chemistry controls the cargo binding to the platform. Transport is controlled by selectively inducing conformational and configurational changes within an embedded hydrazone rotary switch that steers the robotic arm. In a three-stage operation 79-85 % of 3-mercaptopropanehydrazide molecules are transported in either (chosen) direction between the two platform sites, without the cargo at any time fully dissociating from the machine nor exchanging with other molecules in the bulk.The mechanical manipulation of matter at atomic length-scales has fascinated scientists since it was proposed by Feynman in 'There's Plenty of Room at the Bottom'.

show abstract

Section: Designmentioning

confidence: 99%

Pick-up, transport and release of a molecular cargo using a small-molecule robotic arm

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…Directional movement has been demonstrated in artificial molecular machines (1)(2)(3)(4), using photoexcitation (5)(6)(7)(8)(9)(10)(11) and/or the sequential addition of chemical reagents (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22), and an autonomous chemically-driven molecular rotary motor that operates through a bio-inspired (23) information ratchet mechanism has been described (24,25). Here we report on an alternative class of ratchet mechanism, based on acid-base oscillations, that powers both rotary and linear molecular motors.…”

mentioning

confidence: 99%

Rotary and linear molecular motors driven by pulses of a chemical fuel

Erbaş-Çakmak

Fielden

Karaca

et al. 2017

Science

Self Cite

333

274

View full text Add to dashboard Cite

Acid fuels the motion of a threaded ring A central goal in the construction of molecular-scale machines is the efficient achievement of one-way motion. Erbas-Cakmak et al. developed a class of machines that transmit pH changes into the two-stage guided motion of molecular rings threaded on a linear or cyclic axle. The design relies on temporary blocking groups and landing sites along the axle that toggle between active and passive states in response to acid or base. Trichloroacetic acid initiates the first stage of motion until it is decomposed by base in the solution, spurring the second phase. Science , this issue p. 340

show abstract

“…arnessing external control over a system in an aqueous environment and tuning its properties reversibly on demand has attracted considerable interest across the chemical and biological sciences [1][2][3][4] . The highly dynamic nature of supramolecular non-covalent processes offers versatile tools to utilize and amplify external stimuli in the manipulation of material properties through reversible stimuli-responsive molecular switching 5 .…”

mentioning

confidence: 99%

Orthogonal switching of a single supramolecular complex

et al. 2012

View full text Add to dashboard Cite

Orthogonal control over systems represents an advantage over mono-functional switches as both the nature and order of distinctly different stimuli manifest themselves in a wide array of outcomes. Host-guest complexes with multiple, simultaneously bound guests offer unique opportunities to address a set of 'on' and 'off' states accessible on demand. Here we report cucurbit[8]uril-mediated host-guest heteroternary complexes constructed with both redoxand light-responsive guests in a single, supramolecular entity. The complex responds to orthogonal stimuli in a controlled, reversible manner generating a multifunctional switch between a 'closed' heteroternary complex, a redox-driven 'closed' homoternary complex and a photo-driven 'open' uncomplexed state. We exploit both photochemical and electrochemical control over the supramolecular coding system and its surface wettability to demonstrate the system's complexity, which could be readily visualized on a macroscopic level, thus offering new opportunities in the construction of memory devices.

show abstract

Light‐Driven Transport of a Molecular Walker in Either Direction along a Molecular Track

Cited by 62 publications

References 69 publications

Pick-up, transport and release of a molecular cargo using a small-molecule robotic arm

Pick-up, transport and release of a molecular cargo using a small-molecule robotic arm

Rotary and linear molecular motors driven by pulses of a chemical fuel

Orthogonal switching of a single supramolecular complex

Contact Info

Product

Resources

About