Source 1review2015ACS Nano
Toolkit/artificial molecular pump
artificial molecular pump
Taxonomy: Mechanism Branch / Architecture. Workflows sit above the mechanism and technique branches rather than replacing them.
Summary
This question was answered by turning to radical chemistry and employing the known stabilization behavior of a bipyridinium radical cation and the bisradical dication, generated on reduction of the CBPQT(4+) ring, to pluck rings out of solution and thread them over the charged end of the pump portion of a semidumbbell. On subsequent oxidation, the pump is primed and the rings pass through a one-way door, given a little thermal energy, onto a collecting-chain where they find themselves accumulating where they would rather not be present.
Usefulness & Problems
Why this is useful
This artificial molecular pump uses radical-state recognition and subsequent oxidation to move rings onto a collecting chain where they accumulate in a higher-energy state. The review presents it as a synthetic mimic of biological pumping machinery.; pumping tetracationic rings into high-energy states; accumulating rings on a collecting chain; mimicking biological pumping machinery with a synthetic ratchet
Source:
This artificial molecular pump uses radical-state recognition and subsequent oxidation to move rings onto a collecting chain where they accumulate in a higher-energy state. The review presents it as a synthetic mimic of biological pumping machinery.
Source:
pumping tetracationic rings into high-energy states
Source:
accumulating rings on a collecting chain
Source:
mimicking biological pumping machinery with a synthetic ratchet
Problem solved
It solves the earlier prototype's failure to do work by enabling ring accumulation in an energetically unfavorable location. This is the review's main example of nonequilibrium pumping.; enables uphill transport and accumulation of rings rather than reversible shuttling alone; addresses the prototype limitation where no work was done
Source:
It solves the earlier prototype's failure to do work by enabling ring accumulation in an energetically unfavorable location. This is the review's main example of nonequilibrium pumping.
Source:
enables uphill transport and accumulation of rings rather than reversible shuttling alone
Source:
addresses the prototype limitation where no work was done
Problem links
addresses the prototype limitation where no work was done
LiteratureIt solves the earlier prototype's failure to do work by enabling ring accumulation in an energetically unfavorable location. This is the review's main example of nonequilibrium pumping.
Source:
It solves the earlier prototype's failure to do work by enabling ring accumulation in an energetically unfavorable location. This is the review's main example of nonequilibrium pumping.
enables uphill transport and accumulation of rings rather than reversible shuttling alone
LiteratureIt solves the earlier prototype's failure to do work by enabling ring accumulation in an energetically unfavorable location. This is the review's main example of nonequilibrium pumping.
Source:
It solves the earlier prototype's failure to do work by enabling ring accumulation in an energetically unfavorable location. This is the review's main example of nonequilibrium pumping.
Published Workflows
Objective: Forge a path from equilibrium molecular switches to nonequilibrium artificial molecular pumps that can move rings uphill into high-energy states and perform work-like pumping behavior.
Why it works: The review describes a progression from reversible switching, to directional but non-working transport, to a pump that first attracts rings and then biases their passage into a collecting region where they accumulate in a less favorable state.
redox-controlled switchingratchet-driven motionradical-state recognitionone-way transportmolecular designredox cyclinglight-assisted operation
Stages
- 1.Equilibrium switch launching pad(functional_characterization)
This stage provides the starting architecture and mechanistic baseline for later nonequilibrium pump designs.
Selection: Establish reversible redox-controlled ring shuttling between two recognition sites in a bistable [2]rotaxane.
- 2.Directional pump prototype design(functional_characterization)
This stage tests whether asymmetry and redox cycling can convert a switch-like system into a directional transport prototype.
Selection: Use an asymmetric dumbbell to obtain relative unidirectional ring movement under oxidative and reductive cycles.
- 3.Radical-chemistry pump redesign(functional_characterization)
This redesign addresses the prototype's inability to do work by changing the recognition logic so rings can be accumulated in a higher-energy state.
Selection: Make the recognition interaction attractive initially and then repulsive by using radical-state chemistry to capture, thread, and displace rings.
- 4.Autonomy-oriented theoretical extension(decision_gate)
The review explicitly looks beyond the current pump to future autonomous operation.
Selection: Consider what measures would be needed to render the state-of-the-art artificial molecular pump autonomous.
Steps
- 1.Build a bistable redox-switchable rotaxanelaunching architecture
Create a controllable molecular switch with two recognition sites for ring shuttling.
The review presents the bistable [2]rotaxane as the launching pad before attempting nonequilibrium pumping.
- 2.Introduce asymmetry to bias ring entry and exitdirectional transport prototype
Convert reversible switching logic into relative unidirectional ring movement.
This follows the equilibrium switch because directional transport is needed before true pumping can be attempted.
- 3.Cycle oxidation and reduction to test directional transport
Evaluate whether rings enter from one end during oxidation and leave from the other during reduction.
The review uses this operational test to show that the prototype achieves ratchet-driven translational motion but still fails to do work.
- 4.Redesign recognition to be attractive first and repulsive laterwork-performing pump architecture
Overcome the prototype's lack of work output and residual attraction after reduction.
The review explicitly motivates this redesign by asking what happens if the recognition site is attractive initially and then becomes repulsive.
- 5.Capture, thread, and accumulate rings on a collecting chain
Demonstrate that rings can be plucked from solution, threaded over the charged end, and moved through a one-way door onto a collecting chain.
This is the confirmatory functional outcome that distinguishes pumping from mere directional motion.
Taxonomy & Function
Primary hierarchy
Mechanism Branch
Architecture: A reusable architecture pattern for arranging parts into an engineered system.
Mechanisms
kinetic ratcheting via a one-way doornonequilibrium accumulationradical-state molecular recognitionredox cyclingthreading/translational motion of a mechanically interlocked ringTechniques
Computational DesignTarget processes
No target processes tagged yet.
Input: Thermal
Implementation Constraints
cofactor dependency: cofactor requirement unknownencoding mode: genetically encodedimplementation constraint: context specific validationoperating role: actuator
The design requires a semidumbbell pump architecture, CBPQT(4+) rings, access to reduced radical states, and an oxidation step that primes one-way transport. The abstract also notes a need for some thermal energy during passage onto the collecting chain.; requires CBPQT(4+) ring reduction to radical states; requires a semidumbbell pump architecture with a charged end and collecting chain; requires oxidation after threading to prime passage through a one-way door; requires thermal energy for passage onto the collecting chain
The abstract does not claim that the state-of-the-art pump is autonomous. Instead, autonomy is discussed as a future theoretical design goal.; the abstract discusses autonomy only as a theoretical future goal rather than an achieved property
Validation
Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication
Supporting Sources
Ranked Claims
A bistable [2]rotaxane can serve as a launching architecture for designing nonequilibrium molecular pumps.
The molecular pump prototype exhibits relative unidirectional ring movement on an asymmetric dumbbell under redox cycling.
The state-of-the-art artificial molecular pump mimics biological pumping machinery by accumulating rings where they would rather not be present.
Autonomous operation of the artificial molecular pump is discussed as a theoretical future design goal rather than a demonstrated property in the abstract.
The early molecular pump prototype demonstrates ratchet-driven translational motion but does not do work because the ring enters from one end and leaves from the other.
Molecular switches operate near equilibrium, so work done during switching is undone during reset.
Radical chemistry based on reduced CBPQT(4+) states enables ring capture, threading, and subsequent accumulation on a collecting chain in an artificial molecular pump.
Approval Evidence
1 source4 linked approval claimsfirst-pass slug artificial-molecular-pump
This question was answered by turning to radical chemistry and employing the known stabilization behavior of a bipyridinium radical cation and the bisradical dication, generated on reduction of the CBPQT(4+) ring, to pluck rings out of solution and thread them over the charged end of the pump portion of a semidumbbell. On subsequent oxidation, the pump is primed and the rings pass through a one-way door, given a little thermal energy, onto a collecting-chain where they find themselves accumulating where they would rather not be present.
Source:
design transitionsupports
A bistable [2]rotaxane can serve as a launching architecture for designing nonequilibrium molecular pumps.
Source:
functional summarysupports
The state-of-the-art artificial molecular pump mimics biological pumping machinery by accumulating rings where they would rather not be present.
Source:
future directionsupports
Autonomous operation of the artificial molecular pump is discussed as a theoretical future design goal rather than a demonstrated property in the abstract.
Source:
mechanistic summarysupports
Radical chemistry based on reduced CBPQT(4+) states enables ring capture, threading, and subsequent accumulation on a collecting chain in an artificial molecular pump.
Source:
Comparisons
Source-stated alternatives
The review contrasts this pump with bistable molecular switches and with an earlier pump prototype that showed directional motion without work. It also situates the system within mechanically interlocked molecules such as pseudo- and semirotaxanes.
Source:
The review contrasts this pump with bistable molecular switches and with an earlier pump prototype that showed directional motion without work. It also situates the system within mechanically interlocked molecules such as pseudo- and semirotaxanes.
Source-backed strengths
uses radical chemistry to attract and then reposition rings; supports accumulation of rings in a less favorable state on a collecting chain; mimics biological pumping machinery
Source:
uses radical chemistry to attract and then reposition rings
Source:
supports accumulation of rings in a less favorable state on a collecting chain
Source:
mimics biological pumping machinery
Compared with PRS promoter-driven channelrhodopsin-2 lentiviral vector
artificial molecular pump and PRS promoter-driven channelrhodopsin-2 lentiviral vector address a similar problem space.
Shared frame: same top-level item type; same primary input modality: thermal
Compared with single guide RNA array for multiplexed gene activation
artificial molecular pump and single guide RNA array for multiplexed gene activation address a similar problem space.
Shared frame: same top-level item type; same primary input modality: thermal
Compared with Teniposide-nonbinding STING double mutant variant
artificial molecular pump and Teniposide-nonbinding STING double mutant variant address a similar problem space.
Shared frame: same top-level item type; same primary input modality: thermal
Ranked Citations
- 1.