Synthetic Molecular Motors: Thermal N Inversion and Directional Photoinduced CN Bond Rotation of Camphorquinone Imines

Greb, Lutz; Eichhöfer, Andreas; Lehn, Jean‐Marie

doi:10.1002/anie.201506691

Cited by 93 publications

(97 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In a follow-up study, the authors give more details on the mechanism of the photochemical syn-anti isomerization of the C=N bond. 117 This process is expected to be directional due to the placement of a stereogenic center close to the imine. Though theoretical studies confirm this assumption, experimental proof is not included in the initial study.…”

Section: Iminesmentioning

confidence: 99%

Artificial molecular motors

et al. 2017

View full text Add to dashboard Cite

Motor proteins are nature's solution for directing movement at the molecular level. The field of artificial molecular motors takes inspiration from these tiny but powerful machines. Although directional motion on the nanoscale performed by synthetic molecular machines is a relatively new development, significant advances have been made. In this review an overview is given of the principal designs of artificial molecular motors and their modes of operation. Although synthetic molecular motors have also found widespread application as (multistate) switches, we focus on the control of directional movement, both at the molecular scale and at larger magnitudes. We identify some key challenges remaining in the field.

show abstract

Section: Iminesmentioning

confidence: 99%

Artificial molecular motors

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Interestingly, these motors can be operated by a mechanism similar to that of overcrowded alkenes, where each UV-induced photochemical step is followed by a thermal step, [32] or by a simpler mechanism involving only photochemical steps powered by UV or visible light. [33] The last category of rotary motors is structurally very different from the previous categories, consisting of mechanically interlocked ring-shaped molecules that form so-called catenanes (from catena, the Latin word for chain). Such motors, exemplified here by a [3]catenane with 3 interlocked rings (system 6 in Figure 1), [34] are synthesized by the type of methods pioneered by Nobel Laureates Sauvage and Stoddart in the 1980s and 1990s.…”

Section: R Ota R Y M Ol Ecu L a R Mot Orsmentioning

confidence: 99%

Quantum chemical design of rotary molecular motors

Oruganti

Wang

Durbeej

2017

Int J of Quantum Chemistry

View full text Add to dashboard Cite

This tutorial review describes how recent quantum chemical calculations and non-adiabatic molecular dynamics simulations have provided valuable guidelines and insights for the design of more powerful synthetic rotary molecular motors. Following a brief overview of the various types of rotary motors synthesized to date, we present computationally identified steric and electronic approaches to significantly reduce the free-energy barriers of the critical thermal isomerization steps of chiral overcrowded alkenes, a main class of motors whose potential for many different kinds of applications is well documented. Furthermore, we describe how computational research in this field has provided new motor designs that differ from overcrowded alkenes by either (1) completing a full 3608 rotation through fewer steps, (2) exhibiting more efficient photochemical steps, or (3) requiring fewer chiral features for their function, including a design that even in the absence of a stereocenter achieves unidirectional rotary motion from two Z/E photoisomerizations alone.chirality, molecular motors, non-adiabatic molecular dynamics, photoisomerization, steric interactions | I N TR ODU C TI ONIn this tutorial review, we give an account of how quantum chemical research has contributed to advance the field of artificial molecular machines.This field [1][2][3][4][5][6][7][8][9][10][11] is devoted to the fabrication of molecular systems capable of performing the same type of machine-like functions that Nature-made protein complexes carry out in order to, among other things, propel cells, store energy in cells, equip cells with transport systems, and generate biomechanical forces. [12][13][14] Although artificial molecular machines are yet to make an impact on our everyday lives, the field is currently undergoing a rapid expansion both in terms of what man-made molecules can accomplish and the areas of expertise of the scientists drawn to the field. In many ways, this development, envisioned already in 1959 by Richard Feynman in his prophetic "There's Plenty of Room at the Bottom" lecture, [15] is testament to the groundbreaking work on the design and synthesis of molecular machines [16][17][18][19][20][21][22][23][24][25] for which Jean-Pierre Sauvage, Sir J. Fraser Stoddart and Bernard (Ben) L. Feringa were awarded the Nobel Prize in Chemistry 2016.While a molecular machine can be defined as "an assembly of a discrete number of molecular components designed to perform mechanical-like movements (output) as a consequence of appropriate external stimuli (input)," [2] this tutorial review focuses on the subset of such systems known as molecular motors. Loosely speaking, molecular motors are molecules that can produce net work by absorbing external energy and converting the energy into directed (non-random) mechanical motion in a controllable fashion. The ability to produce net work is the distinguishing feature of molecular motors vis-a-vis molecular switches, the latter of which sustain back-and-forth motion but not the continuous m...

show abstract

“…[1] Particular interest has been paid to light-driven molecular motors,w hich convert light energy into molecular motion. As has been demonstrated for instance by Lehn [3] and Feringa, [4] as ophisticated design of the molecular motor allows for the coupling of several photochemically and thermally accessible switching steps and thus directed rotational motion. As has been demonstrated for instance by Lehn [3] and Feringa, [4] as ophisticated design of the molecular motor allows for the coupling of several photochemically and thermally accessible switching steps and thus directed rotational motion.…”

mentioning

confidence: 93%

“…[15] In ad etailed study on matrix effects,w eh ighlighted the extraordinary conformational sensitivity of MI-VCD spectroscopy by showing that the small chiral amine a-phenylethyl amine is significantly deformed due to matrix packing effects. [3] In acetonitrile solution, the (E)-1 isomer is favored over the (Z)-1 isomer (99:1), while the isomer ratio changes to 21:79 in the photostationary state after irradiation with light of l = 365 nm. [3] In acetonitrile solution, the (E)-1 isomer is favored over the (Z)-1 isomer (99:1), while the isomer ratio changes to 21:79 in the photostationary state after irradiation with light of l = 365 nm.…”

mentioning

confidence: 98%

Photoisomerization of a Chiral Imine Molecular Switch Followed by Matrix‐Isolation VCD Spectroscopy

2017

View full text Add to dashboard Cite

Characterizing the stereochemistry of transient photoisomerization products remains a big challenge for the design of molecular machines, such as unidirectional molecular motors. Often these states are not stable long enough to be characterized in detail using conventional spectroscopic tools. The structurally simple camphorquinone imine 1 serves to illustrate the advantage of combining the matrix-isolation technique with vibrational circular dichroism (VCD) spectroscopy for the investigation of photoisomerizations of chiral molecules. In particular, it is shown that both (E)- and (Z)-1 can be generated photochemically at cryogenic temperatures in an argon matrix, and more importantly, that the stereochemistry of both switching states can be characterized reliably.

show abstract

Synthetic Molecular Motors: Thermal N Inversion and Directional Photoinduced CN Bond Rotation of Camphorquinone Imines

Cited by 93 publications

References 40 publications

Artificial molecular motors

Artificial molecular motors

Quantum chemical design of rotary molecular motors

Photoisomerization of a Chiral Imine Molecular Switch Followed by Matrix‐Isolation VCD Spectroscopy

Contact Info

Product

Resources

About