Rotaxanes

Cyclobutanes

Rotaxane

Polyrotaxane

Pauson-Khand reaction

Polyyne

Catenane

Mechanically interlocked molecular architectures

Ribosomally synthesized and post-translationally modified peptides

Polycatenane

Carbon nanotube chemistry

William Dichtel

Christoph Weder

Supramolecular chemistry

Viologen

Cluster of Excellence Frankfurt Macromolecular Complexes

Nanotechnology

Vincenzo Balzani

Α-Cyclodextrin

Jean-Pierre Sauvage

Cyclodextrin

Alexandra Slawin

Harry Anderson (chemist)

Cucurbituril

Cycloparaphenylene

Cyanostar

Ramesh Jasti

Molecular machine

Kinetic isotope effect

Soft matter

Copper compounds

Copper

Synthesis7

• Much of the research concerning rotaxanes and other mechanically interlocked molecular architectures, such as catenanes, has been focused on their efficient synthesis or their utilization as artificial molecular machines. (wikipedia.org)
• The earliest reported synthesis of a rotaxane in 1967 relied on the statistical probability that if two halves of a dumbbell-shaped molecule were reacted in the presence of a macrocycle that some small percentage would connect through the ring. (wikipedia.org)
• However, the synthesis of rotaxanes has advanced significantly and efficient yields can be obtained by preorganizing the components utilizing hydrogen bonding, metal coordination, hydrophobic forces, covalent bonds, or coulombic interactions. (wikipedia.org)
• Synthesis of thiophene-capped [2]rotaxanes. (mpg.de)
• 2022 ) Polyyne [3]rotaxanes: Synthesis via dicobalt carbonyl complexes and enhanced stability. (academictree.org)
• Mechanochemical synthesis of the smallest [2]rotaxane. (beilstein-journals.org)
• Mechanochemical liquid-assisted one-pot two-step synthesis of [2]rotaxanes under high-speed vibrati. (beilstein-journals.org)

Catenanes1

• Landmark achievements of his lab include the first synthetic Brownian ratchet molecular motors (2003), synthetic molecular machines able to perform macroscopic work (2005), the invention of catalytic routes to rotaxanes, catenanes and knots, and the first molecular weaving (2020). (gonzaga.edu)

Functional rotaxanes1

• So far, the repertoire of available functional rotaxanes as building blocks for the preparation of stimuli-responsive polymers remains limited. (chemistryviews.org)

Molecular11

• A rotaxane (from Latin rota 'wheel', and axis 'axle') is a mechanically interlocked molecular architecture consisting of a dumbbell-shaped molecule which is threaded through a macrocycle (see graphical representation). (wikipedia.org)
• Rotaxane-based molecular machines have been of initial interest for their potential use in molecular electronics as logic molecular switching elements and as molecular shuttles. (wikipedia.org)
• Controlling the position of the macrocycle allows the rotaxane to function as a molecular switch, with each possible location of the macrocycle corresponding to a different state. (wikipedia.org)
• Rotaxane based systems have also been shown to function as molecular muscles. (wikipedia.org)
• Researchers have manipulated structures called rotaxanes that could pave the way for new possibilities in molecular computing, sensors, and drug delivery. (designnews.com)
• Hokkaido University researchers Minami Ebe, Asuka Soga, Takuya Isono, and Toshifumi Satoh, who worked with rotaxanes, or interlocked molecular structures, in their research to develop what are called 'network polymers. (designnews.com)
• Scientists from Hokkaido University and other institutions in Japan worked with rotaxanes, or interlocked molecular structures, in their research to develop what are called 'network polymers. (designnews.com)
• The team has taken current research surrounding these structures further through the creation of macro-rotaxanes that have multicyclic wheels interlocked with several high-molecular-weight axles. (designnews.com)
• En 1996, il est retourné aux Pays-Bas pour joindre le FOM Institute for Atomic and Molecular Physics à Amsterdam où il a mis au point un nouveau type de " streak cameras " pour l infrarouge. (epfl.ch)
• Among his developments based on rotaxanes are a molecular lift, a molecular muscle and a molecule-based computer chip. (nobelprize.org)
• The third application is based on the idea that low-barrier molecular rotary motors having rotaxane architecture can be constructed using a cucurbituril host and a polyyne guest serving as stator and rotator, respectively. (openu.ac.il)

Polymers2

• According to the researchers, this kind of rotaxane bearing functional groups is a powerful platform for preparing stimuli-responsive polymers. (chemistryviews.org)
• A [2]rotaxane cross-linker ( RC ) with one vinyl group in each component was designed and synthesized as a vinylic cross-linker for highly toughened network polymers, which were prepared from the radical polymerization of n -butyl acrylate and 2-ethylhexyl acrylate in the presence of 0.5 mol% of RC . (rsc.org)

Molecule3

• The partial macrocycle then undergoes a ring closing reaction around the dumbbell-shaped molecule, forming the rotaxane. (wikipedia.org)
• Rotaxanes are composed of a linear 'axle' molecule penetrating one or more cyclic 'wheel' molecules, with bulky groups at the end of the axle that prevent the wheels from coming off. (designnews.com)
• Article: Akira Harada, Osaka University, Single-Molecule Imaging of Rotaxanes Immobilized on Glass Substrates: Observation of Rotary Movement, Angewandte Chemie International Edition 2008, 47, No. 32, 6077? (science20.com)

20201

• 2020 ) Photochemical Unmasking of Polyyne Rotaxanes. (academictree.org)

Axle3

• Da-Hui Qu and colleagues, East China University of Science and Technology, Shanghai, have designed, synthesized, and characterized a functional [2]rotaxane with two alkenyl bonds on the macrocycle and the axle, respectively. (chemistryviews.org)
• A series of rotaxanes, with phenolic axle centerpieces and tetralactam macrocycles as the wheels, has been prepared in good yields. (uni-regensburg.de)
• 83%) using a [2]rotaxane diol that has a hydroxy group in each wheel and axle component. (elsevierpure.com)

Abstract1

• abstract = "The organization of trisradical rotaxanes within the channels of a Zr6-based metal-organic framework (NU-1000) has been achieved postsynthetically by solvent-assisted ligand incorporation. (york.ac.uk)

Dumbbell-shaped1

• To do this, they built upon their previous work, published last year, in which they developed a type of polyurethane that contains stress-sensing rotaxane consisting of ring-shaped fluorescent molecules threaded on dumbbell-shaped molecules featuring so-called "quencher groups" - which decrease the fluorescence intensity of a given substance - at their centre. (canplastics.com)

Structures5

• We think the multicyclic structures in these macro-rotaxanes could be useful as non-leaching additives, permanently retained in a polymer network by the way they hold onto several neighboring polymer chains," he said. (designnews.com)
• Rotaxane dendrimers with hyperbranched macromolecular interlocked structures and size modulation capacity demonstrate drug binding and release ability upon external stimuli. (edu.hk)
• The traditional prepolymer method was applied to introduce rotaxane structures at different locations in the soft segment and at the boundary between soft and hard segments. (elsevierpure.com)
• Differential scanning calorimetry (DSC), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FT-IR), and synchrotron X-ray measurements revealed that the phase-separated structures of the SPUs were almost independent of the amount of rotaxane. (elsevierpure.com)
• The highly movable rotaxane scaffold was even effective for toughening the SPU, which is a physically cross-linked network, without changing their phase-separated structures. (elsevierpure.com)

Precursors1

• Robust Zr(IV)-carboxylate bonds are forged between the Zr clusters of NU-1000 and carboxylic acid groups of rotaxane precursors (semirotaxanes) as part of this building block replacement strategy. (york.ac.uk)

Electrostatic1

• Instead of suppressing the shuttling motion completely, as observed in other rotaxanes, our rotaxane is the first system in which electrostatic interactions modulate the speed of the mechanical motion between a fast and a slow motion state as a response to a reversible external stimulus. (uni-regensburg.de)

Pseudorotaxane1

• This dynamic complex or pseudorotaxane is then converted to the rotaxane by reacting the ends of the threaded guest with large groups, preventing disassociation. (wikipedia.org)

Fraser Stoddart1

• The second step was taken by Fraser Stoddart in 1991, when he developed a rotaxane . (nobelprize.org)

Cyclic2

• Cyclic voltammetry measurements performed on electroactive thin films of the resulting material indicate that redox-active viologen subunits located on the rotaxane components can be accessed electrochemically in the solid state. (york.ac.uk)
• In the current study, the researchers developed three new polyurethanes that glowed blue, green or orange when stretched, demonstrating that the colour can be tailored simply by using different cyclic fluorescent rings in the rotaxanes. (canplastics.com)

Fluorescent1

• Chapter VIII demonstrates using a nanohoop rotaxane as a fluorescent probe for H2S. (uoregon.edu)

Molecules2

• A diacylaminopyridine moiety was incorporated into the thread for directing [2]rotaxane formation further allowing the association of complementary small molecules. (rsc.org)
• This gave snapshots of individual rotaxane molecules in the form of emission patterns. (science20.com)

Compounds1

• This paves the way to create even more complex geometric compounds such as 'rotaxane' and 'trefoil knot' at a similar scale. (nanowerk.com)

Researchers2

• As the subject of their study the researchers chose a rotaxane. (science20.com)
• The researchers showed that the cuff of the rotaxane does not rotate if the sample is dry. (science20.com)

Macrocycle2

• To obtain a reasonable quantity of rotaxane, the macrocycle was attached to a solid-phase support and treated with both halves of the dumbbell 70 times and then severed from the support to give a 6% yield. (wikipedia.org)
• one part of the thread is then threaded to the macrocycle, forming a semi rotaxane, and end is closed of by the other part of the thread forming the rotaxane. (wikipedia.org)

Rotary1

• The rotary movement of a chromophore-modified alpha-cyclodextrin (alpha-CD) was studied in a rotaxane structure attached to a glass substrate. (science20.com)

Mechanical1

• The mechanical properties of the formed SPUs were evaluated via tensile tests, and we determined that the introduction of an appropriate amount of rotaxane structure improved their extensibility, toughness, and stress-relaxing properties. (elsevierpure.com)

Structure1

• The threaded rotaxane structure is confirmed in the gas phase by tandem mass spectrometric experiments through a detailed fragmentation pattern analysis, in solution by NMR spectroscopy, and in the solid state through X-ray crystallography. (uni-regensburg.de)

Representation1

• a) Schematic representation for the construction of a [2]rotaxane. (beilstein-journals.org)

Rings2

• Rotaxane Rings Promote Oblique Packing and Extended Lifetimes in DNA-T" by Matthew S. Barclay, Simon K. Roy et al. (boisestate.edu)
• Here, we show that adding rotaxane rings to squaraine dyes templated with DNA promotes an elusive oblique packing arrangement with highly desirable optical properties. (boisestate.edu)

Groups1

• The induction of active and functional groups make the preparation of rotaxanes more difficult and complicated. (chemistryviews.org)

Components1

• The two components of a rotaxane are kinetically trapped since the ends of the dumbbell (often called stoppers) are larger than the internal diameter of the ring and prevent dissociation (unthreading) of the components since this would require significant distortion of the covalent bonds. (wikipedia.org)

Systems1

• The rotaxane-based systems were tested as organocatalysts in asymmetric enamine-mediated processes, revealing a significantly improved catalytic ability if compared with the non-interlocked thread. (rsc.org)

Chain1

• One side of the rotaxane chain is terminated by a bulky stopper bearing three long alkyl chains to prevent the macrocyclic moiety from slipping out the thread. (chemistryviews.org)

Interest1

• The research reflects a renewed interest in working with rotaxanes, which initially were regarded as chemical curiosities by the scientific community. (designnews.com)

Method2

• The method of slipping is one which exploits the thermodynamic stability of the rotaxane. (wikipedia.org)
• Herein, we reported a novel method to display the in situ spatial distribution of label-free monodispersed type III rotaxane dendrimers (RDs) G1 (first generation, size ∼1.5 nm) and G2 (second generation, size ∼5 nm) that were explored as potential drug vehicles in spleen tissue by using matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-MSI). (edu.hk)

Type1

• The self-inclusion behavior of a tetrathiafulvalene-containing lasso-type pseudo[1]rotaxane can be reversibly switched between a threaded and non-threaded state by redox-stimuli. (sfb765.de)

Chemical1

• These rotaxane machines can be manipulated both by chemical and photochemical inputs. (wikipedia.org)