scholarly journals Molecular machines operated by light

2008 ◽  
Vol 6 (3) ◽  
pp. 325-339 ◽  
Author(s):  
Alberto Credi ◽  
Margherita Venturi
Keyword(s):  
Molecular Biology ◽  
Chemical Reactions ◽  
Molecular Motors ◽  
Molecular Size ◽  
Molecular Machines ◽  
Spectroscopic Methods ◽  
Material Base ◽  
Photochemical Processes ◽  
Biological World ◽  
Light Excitation

AbstractThe bottom-up construction and operation of machines and motors of molecular size is a topic of great interest in nanoscience, and a fascinating challenge of nanotechnology. Researchers in this field are stimulated and inspired by the outstanding progress of molecular biology that has begun to reveal the secrets of the natural nanomachines which constitute the material base of life. Like their macroscopic counterparts, nanoscale machines need energy to operate. Most molecular motors of the biological world are fueled by chemical reactions, but research in the last fifteen years has demonstrated that light energy can be used to power nanomachines by exploiting photochemical processes in appropriately designed artificial systems. As a matter of fact, light excitation exhibits several advantages with regard to the operation of the machine, and can also be used to monitor its state through spectroscopic methods. In this review we will illustrate the design principles at the basis of photochemically driven molecular machines, and we will describe a few examples based on rotaxane-type structures investigated in our laboratories.

scholarly journals Rotaxane-based molecular machines operated by photoinduced electron transfer

2005 ◽  
Vol 77 (6) ◽  
pp. 1051-1057 ◽  
Author(s):  
Alberto Credi ◽  
Belén Ferrer
Keyword(s):  
Electron Transfer ◽  
Chemical Reactions ◽  
Molecular Motors ◽  
Photoinduced Electron Transfer ◽  
Molecular Machines ◽  
Good Choice ◽  
External Stimulation ◽  
Biological World ◽  
Electron Transfer Processes ◽  
Molecular Components

A molecular machine is an assembly of a definite number of molecular components designed to perform mechanical motions as a result of an appropriate external stimulation. Like their macroscopic counterparts, nanoscale machines need energy to operate. Energy can be supplied through (i) chemical reactions, (ii) electrochemical processes, and (iii) photoinduced processes. Although most molecular motors of the biological world are fueled by chemical reactions, for several reasons light is a very good choice to operate artificial molecular machines. Rotaxanes, owing to their peculiar architecture, are attractive candidates for the construction of artificial nanoscale machines. By adopting an incrementally staged design strategy, photoinduced electron-transfer processes have been engineered within rotaxane-type structures with the purpose of obtaining light-powered molecular machines. Such an approach is illustrated by describing the behavior of prototypes investigated in our laboratories.

Artificial Molecular Motors Powered by Light

2006 ◽  
Vol 59 (3) ◽  
pp. 157 ◽  
Author(s):  
Alberto Credi
Keyword(s):  
Molecular Motors ◽  
Energy Supply ◽  
Molecular Size ◽  
Design Principles ◽  
Light Energy ◽  
Bottom Up ◽  
Waste Products ◽  
Photochemical Processes ◽  
Autonomous Operation

The bottom-up construction and operation of machines and motors of molecular size is a topic of great interest in nanoscience, and a fascinating challenge of nanotechnology. The problem of the energy supply to make molecular motors work is of the greatest importance. Research in the last ten years has demonstrated that light energy can indeed be used to power artificial nanomotors by exploiting photochemical processes in appropriately designed systems. More recently, it has become clear that under many aspects light is the best choice to power molecular motors; for example, systems that show autonomous operation and do not generate waste products can be obtained. This review is intended to discuss the design principles at the basis of light-driven artificial nanomotors, and provide an up-to-date overview on the prototype systems that have been developed.

scholarly journals Molecular machines operating on the nanoscale: from classical to quantum

2016 ◽  
Vol 7 ◽  
pp. 328-350 ◽  
Author(s):  
Igor Goychuk
Keyword(s):  
Molecular Motors ◽  
High Performance ◽  
Molecular Machines ◽  
Thermal Fluctuations ◽  
Maximum Power ◽  
Thermodynamic Efficiency ◽  
Fluctuation Dissipation ◽  
Fluctuation Dissipation Theorem ◽  
Physical Features

The main physical features and operating principles of isothermal nanomachines in the microworld, common to both classical and quantum machines, are reviewed. Special attention is paid to the dual, constructive role of dissipation and thermal fluctuations, the fluctuation–dissipation theorem, heat losses and free energy transduction, thermodynamic efficiency, and thermodynamic efficiency at maximum power. Several basic models are considered and discussed to highlight generic physical features. This work examines some common fallacies that continue to plague the literature. In particular, the erroneous beliefs that one should minimize friction and lower the temperature for high performance of Brownian machines, and that the thermodynamic efficiency at maximum power cannot exceed one-half are discussed. The emerging topic of anomalous molecular motors operating subdiffusively but very efficiently in the viscoelastic environment of living cells is also discussed.

scholarly journals Stochastically pumped adaptation and directional motion of molecular machines

2018 ◽  
Vol 115 (38) ◽  
pp. 9405-9413 ◽  
Author(s):  
R. Dean Astumian
Keyword(s):  
Single Molecule ◽  
Molecular Motors ◽  
High Efficiency ◽  
Probability Distributions ◽  
Molecular Machines ◽  
High Energy ◽  
Stochastic Thermodynamics ◽  
Recent Developments ◽  
Directional Motion ◽  
External Fluctuations

Recent developments in synthetic molecular motors and pumps have sprung from a remarkable confluence of experiment and theory. Synthetic accomplishments have facilitated the ability to design and create molecules, many of them featuring mechanically bonded components, to carry out specific functions in their environment—walking along a polymeric track, unidirectional circling of one ring about another, synthesizing stereoisomers according to an external protocol, or pumping rings onto a long rod-like molecule to form and maintain high-energy, complex, nonequilibrium structures from simpler antecedents. Progress in the theory of nanoscale stochastic thermodynamics, specifically the generalization and extension of the principle of microscopic reversibility to the single-molecule regime, has enhanced the understanding of the design requirements for achieving strong unidirectional motion and high efficiency of these synthetic molecular machines for harnessing energy from external fluctuations to carry out mechanical and/or chemical functions in their environment. A key insight is that the interaction between the fluctuations and the transition state energies plays a central role in determining the steady-state concentrations. Kinetic asymmetry, a requirement for stochastic adaptation, occurs when there is an imbalance in the effect of the fluctuations on the forward and reverse rate constants. Because of strong viscosity, the motions of the machine can be viewed as mechanical equilibrium processes where mechanical resonances are simply impossible but where the probability distributions for the state occupancies and trajectories are very different from those that would be expected at thermodynamic equilibrium.

scholarly journals DNA Origami Nanomachines

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1766 ◽  
Author(s):  
Masayuki Endo ◽  
Hiroshi Sugiyama
Keyword(s):  
Dna Sequences ◽  
Molecular Motors ◽  
Molecular Machines ◽  
Dna Origami ◽  
Dna Nanostructures ◽  
Molecular Systems ◽  
Nanoscale Structures ◽  
Research Fields ◽  
Dna Strands ◽  
External Stimuli

DNA can assemble various molecules and nanomaterials in a programmed fashion and is a powerful tool in the nanotechnology and biology research fields. DNA also allows the construction of desired nanoscale structures via the design of DNA sequences. Structural nanotechnology, especially DNA origami, is widely used to design and create functionalized nanostructures and devices. In addition, DNA molecular machines have been created and are operated by specific DNA strands and external stimuli to perform linear, rotational, and reciprocating movements. Furthermore, complicated molecular systems have been created on DNA nanostructures by arranging multiple molecules and molecular machines precisely to mimic biological systems. Currently, DNA nanomachines, such as molecular motors, are operated on DNA nanostructures. Dynamic DNA nanostructures that have a mechanically controllable system have also been developed. In this review, we describe recent research on new DNA nanomachines and nanosystems that were built on designed DNA nanostructures.

scholarly journals Green light powered molecular state motor enabling eight-shaped unidirectional rotation

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Aaron Gerwien ◽  
Peter Mayer ◽  
Henry Dube
Keyword(s):  
Molecular Motors ◽  
Molecular Level ◽  
Molecular Motor ◽  
Green Light ◽  
Molecular Machines ◽  
Molecular State ◽  
Molecular Devices ◽  
External Energy ◽  
Fixed Sequence ◽  
Crossing Point

Abstract Molecular motors convert external energy into directional motions at the nano-scales. To date unidirectional circular rotations and linear motions have been realized but more complex directional trajectories remain unexplored on the molecular level. In this work we present a molecular motor powered by green light allowing to produce an eight-shaped geometry change during its unidirectional rotation around the central molecular axis. Motor motion proceeds in four different steps, which alternate between light powered double bond isomerizations and thermal hula-twist isomerizations. The result is a fixed sequence of populating four different isomers in a fully unidirectional trajectory possessing one crossing point. This motor system opens up unexplored avenues for the construction and mechanisms of molecular machines and will therefore not only significantly expand the toolbox of responsive molecular devices but also enable very different applications in the field of miniaturized technology than currently possible.

scholarly journals Beyond switches: Rotaxane- and catenane-based synthetic molecular motors

2008 ◽  
Vol 80 (1) ◽  
pp. 17-29 ◽  
Author(s):  
Euan R. Kay ◽  
David A. Leigh
Keyword(s):  
Molecular Motors ◽  
Physical Science ◽  
Statistical Physics ◽  
Biological Process ◽  
Molecular Level ◽  
Molecular Machines ◽  
Interlocked Molecules ◽  
Recent Developments ◽  
New Generation ◽  
First Time

Nature uses molecular motors and machines in virtually every significant biological process, but learning how to design and assemble simpler artificial structures that function through controlled molecular-level motion is a major challenge for contemporary physical science. The established engineering principles of the macroscopic world can offer little more than inspiration to the molecular engineer who creates devices for an environment where everything is constantly moving and being buffeted by other atoms and molecules. Rather, experimental designs for working molecular machines must follow principles derived from chemical kinetics, thermodynamics, and nonequilibrium statistical physics. The remarkable characteristics of interlocked molecules make them particularly useful for investigating the control of motion at the molecular level. Yet, the vast majority of synthetic molecular machines studied to date are simple two-state switches. Here we outline recent developments from our laboratory that demonstrate more complex molecular machine functions. This new generation of synthetic molecular machines can move continuously and progressively away from equilibrium, and they may be considered true prototypical molecular motors. The examples discussed exemplify two, fundamentally different, "Brownian ratchet" mechanisms previously developed in theoretical statistical physics and realized experimentally in molecular-level devices for the first time in these systems.

scholarly journals Docking and in vitro molecular biology studies of p-anisidine-appended 1-hydroxy-2-acetonapthanone Schiff base lanthanum(iii) complexes

RSC Advances ◽  
2020 ◽  
Vol 10 (28) ◽  
pp. 16457-16472
Author(s):  
V. Sathiyanarayanan ◽  
P. Varun Prasath ◽  
P. Chandra Sekhar ◽  
K. Ravichandran ◽  
D. Easwaramoorthy ◽  
...  
Keyword(s):  
Schiff Base ◽  
Molecular Biology ◽  
Spectroscopic Methods

A new series of lanthanum(iii) complexes was synthesized using a p-anisidine-appended 1-hydroxy-2-acetonapthanone (3) Schiff base and characterized via spectroscopic methods.

Iridoide aus einigen Teucrium-und Ajuga-Arten / Iridoids in Some Teucrium and Ajuga Species

1981 ◽  
Vol 36 (9-10) ◽  
pp. 697-707 ◽  
Author(s):  
Johann Ruhdorfer ◽  
Horst Rimpler
Keyword(s):  
Chemical Reactions ◽  
13C Nmr ◽  
Spectroscopic Methods ◽  
Taxonomic Significance ◽  
Relative Configuration ◽  
New Compounds

Abstract of the genus Teucrium and 3 species of the genus Ajuga have been examined for iridoids. Besides the known compounds Harpagid, 8-O-Acetylharpagid, Ajugol, Ajugosid and Reptosid, which we have isolated from species of both genera, two new iridoids Teucardosid (1) [2] and Teuhircosid (5) have been isolated from Teucrium species only. The structure and relative configuration of the new compounds have been determined by spectroscopic methods fH-NMR, 13C-NMR, MS) and some chemical reactions. The taxonomic significance of our results is discussed.

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