scholarly journals Mechanostereochemistry and the mechanical bond

2012 ◽  
Vol 468 (2146) ◽  
pp. 2849-2880 ◽  
Author(s):  
Gokhan Barin ◽  
Ross S. Forgan ◽  
J. Fraser Stoddart
Keyword(s):  
Self Assembly ◽  
Rapid Development ◽  
Synthetic Methods ◽  
Interlocked Molecules ◽  
Fair Game ◽  
Mechanical Bond ◽  
Covalently Linked ◽  
Mechanical Bonds ◽  
Molecular Compounds ◽  
Knots And Links

The chemistry of mechanically interlocked molecules (MIMs), in which two or more covalently linked components are held together by mechanical bonds , has led to the coining of the term mechanostereochemistry to describe a new field of chemistry that embraces many aspects of MIMs, including their syntheses, properties, topologies where relevant and functions where operative. During the rapid development and emergence of the field, the synthesis of MIMs has witnessed the forsaking of the early and grossly inefficient statistical approaches for template-directed protocols, aided and abetted by molecular recognition processes and the tenets of self-assembly. The resounding success of these synthetic protocols, based on templation, has facilitated the design and construction of artificial molecular switches and machines, resulting more and more in the creation of integrated functional systems. This review highlights (i) the range of template-directed synthetic methods being used currently in the preparation of MIMs; (ii) the syntheses of topologically complex knots and links in the form of stable molecular compounds; and (iii) the incorporation of bistable MIMs into many different device settings associated with surfaces, nanoparticles and solid-state materials in response to the needs of particular applications that are perceived to be fair game for mechanostereochemistry.

scholarly journals Self-assembly of TiO2/ZIF-8 nanocomposites for varied photocatalytic CO2 reduction with H2O vapor induced by different synthetic methods

2021 ◽  
Author(s):  
Yan-Hong Zou ◽  
Hai-Ning Wang ◽  
Xing Meng ◽  
Hong-Xu Sun ◽  
Zi-Yan Zhou
Keyword(s):  
Self Assembly ◽  
Co2 Reduction ◽  
Synthetic Methods ◽  
Photocatalytic Performances ◽  
Synthetic Approaches

Different synthetic approaches give birth to different structures, which result in varied photocatalytic performances.

DNA-based self-assembly of nanostructures

2017 ◽  
Author(s):  
Joshua D. Carter ◽  
Chenxiang Lin ◽  
Yan Liu ◽  
Hao Yan ◽  
Thomas H. LaBean
Keyword(s):  
Self Assembly ◽  
Materials Science ◽  
Directed Assembly ◽  
Building Blocks ◽  
Hierarchical Assembly ◽  
Synthetic Dna ◽  
Nanoscale Manufacturing ◽  
Covalently Linked ◽  
Design Construction ◽  
Proteins And Peptides

This article examines the DNA-based self-assembly of nanostructures. It first reviews the development of DNA self-assembly and DNA-directed assembly, focusing on the main strategies and building blocks available in the modern molecular construction toolbox, including the design, construction, and analysis of nanostructures composed entirely of synthetic DNA, as well as origami nanostructures formed from a mixture of synthetic and biological DNA. In particular, it considers the stepwise covalent synthesis of DNA nanomaterials, unmediated assembly of DNA nanomaterials, hierarchical assembly, nucleated assembly, and algorithmic assembly. It then discusses DNA-directed assembly of heteromaterials such as proteins and peptides, gold nanoparticles, and multicomponent nanostructures. It also describes the use of complementary DNA cohesion as 'smart glue' for bringing together covalently linked functional groups, biomolecules, and nanomaterials. Finally, it evaluates the potential future of DNA-based self-assembly for nanoscale manufacturing for applications in medicine, electronics, photonics, and materials science.

A Dynamic Route to Structure and Function: Recent Advances in Imine-Based Organic Nanostructured Materials

2013 ◽  
Vol 66 (1) ◽  
pp. 9 ◽  
Author(s):  
Yi Liu ◽  
Zhan-Ting Li
Keyword(s):  
Self Assembly ◽  
Reaction System ◽  
Functional Materials ◽  
Building Blocks ◽  
The Self ◽  
Interlocked Molecules ◽  
Functional Aspects ◽  
Imine Bond ◽  
And Function ◽  
Dynamic Route

The chemistry of imine bond formation from simple aldehyde and amine precursors is among the most powerful dynamic covalent chemistries employed for the construction of discrete molecular objects and extended molecular frameworks. The reversible nature of the C=N bond confers error-checking and proof-reading capabilities in the self-assembly process within a multi-component reaction system. This review highlights recent progress in the self-assembly of complex organic molecular architectures that are enabled by dynamic imine chemistry, including molecular containers with defined geometry and size, mechanically interlocked molecules, and extended frameworks and polymers, from building blocks with preprogrammed steric and electronic information. The functional aspects associated with the nanometer-scale features not only place these dynamically constructed nanostructures at the frontier of materials sciences, but also bring unprecedented opportunities for the discovery of new functional materials.

Self-assembly of knots and links

2017 ◽  
Vol 2017 (3) ◽  
pp. 034003 ◽  
Author(s):  
Enzo Orlandini ◽  
Guido Polles ◽  
Davide Marenduzzo ◽  
Cristian Micheletti
Keyword(s):  
Self Assembly ◽  
Knots And Links

Template-Directed Syntheses of Catenanes

1997 ◽  
Vol 62 (4) ◽  
pp. 527-557 ◽  
Author(s):  
Martin Bělohradský ◽  
Françisco M. Raymo ◽  
J. Fraser Stoddart
Keyword(s):  
Self Assembly ◽  
Molecular Level ◽  
Covalent Bonds ◽  
Topological Features ◽  
Multistep Synthesis ◽  
Chance Event ◽  
Degree Of Control ◽  
High Degree ◽  
Acyclic Precursor ◽  
Molecular Compounds

The art and science of introducing mechanical-interlocking at the molecular level in order to generate catenanes - molecules composed of two or more macrocyclic components - offers the opportunity of constructing a new range of molecular compounds possessing intriguing properties. However, the topological features displayed by catenanes has rendered the syntheses of such molecular compounds an extremely challenging task for synthetic chemists to address. Their early syntheses were based upon either statistical approaches - the threading of a small amount of a macrocycle on to an acyclic precursor as a chance event - or directed approaches, relying upon the temporary introduction of covalent bonds in the multistep synthesis of a so-called precatenane, followed by its conversion ultimately into a catenane. These approaches afforded catenanes in very low yields overall and only after following tedious and laborious synthetic procedures. Fortunately, however, with the advent of supramolecular chemistry, template-directed methods that allow us to self-assemble [n]catenanes much more efficiently have become available. Numerous successful template-directed syntheses have now emerged - some by chance and others by design. These methods have been based upon (i) metal coordinating, (ii) hydrogen bonding, (iii) solvophobic, and/or (iv) π-π stacking interactions which have been found to govern self-assembly processes to catenated compounds from appropriate precursors. Their relative simplicity, the high degree of control with which they can be employed, and the remarkable efficiency with which they proceed has already provided the opportunity to synthetic chemists to self-assemble a series of [n]catenanes, incorporating from two up to five mechanically-interlocked macrocyclic components.

scholarly journals The thermodynamics of the self-assembly of covalently linked oligomeric naphthalenediimides into helical organic nanotubes

2014 ◽  
Vol 12 (4) ◽  
pp. 607-614 ◽  
Author(s):  
Koujiro Tambara ◽  
John-Carl Olsen ◽  
David E. Hansen ◽  
G. Dan Pantoş
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Covalently Linked ◽  
Organic Nanotubes

Mechanostereochemistry

2010 ◽  
Vol 82 (8) ◽  
pp. 1569-1574 ◽  
Author(s):  
Mark A. Olson ◽  
Youssry Y. Botros ◽  
J. Fraser Stoddart
Keyword(s):  
Mechanical Bond ◽  
Mechanical Bonds ◽  
Noncovalent Bonding ◽  
Configuration And Conformation

Stereochemistry—in both its static and dynamic variants—has progressed apace now for more than a century to incorporate all aspects of covalent, coordinative, and noncovalent bonding at levels of structure which encompass constitution, configuration, and conformation. The advent of the mechanical bond in more recent times is now providing opportunities for the emergence of new stereochemical tenets and concepts, some of which bear close analogies with those of days gone by in chemistry. Since terminology helps to define and disseminate a discipline, we advocate that the term “mechanostereochemistry” be used to describe the chemistry of molecules with mechanical bonds.

scholarly journals Green synthesis via electrolysis in microemulsions

2001 ◽  
Vol 73 (12) ◽  
pp. 1895-1905 ◽  
Author(s):  
James F. Rusling
Keyword(s):  
Turnover Rate ◽  
Recent Progress ◽  
Reaction Pathway ◽  
Reaction Rates ◽  
Synthetic Methods ◽  
Reaction Pathways ◽  
Lower Toxicity ◽  
Reduction Potentials ◽  
Covalently Linked ◽  
High Yields

Electrolysis in microemulsions is a promising approach for environmentally friendly chemical synthetic methods of the future. Employing microemulsions instead of organic solvents for electrosynthesis has the advantages of lower toxicity and cost, high dissolving power for reactants and mediators of unlike solubility, enhancement of reaction rates by controlling the reduction potentials of mediators, possible reaction pathway control, and recycling of microemulsion components. This paper reviews recent progress in using microemulsions for direct and mediated electrosynthesis, including formation of carbon­carbon bonds. Rates of mediated reactions can be controlled by manipulating microemulsion composition. Examples are presented, in which reaction pathways of direct and mediated electrolyses can be controlled with microemulsions to give desired products in high yields. Such control has been demonstrated with dissolved and surface-bound mediators. For a covalently linked scaffold of poly(l-lysine) and cobalt corrin vitamin B12 hexacarboxylate attached to graphite, catalytic turnover rate for reduction of 1,2-dibromocylcohexane was optimized by optimizing microemulsion composition.

Framework Functionalization of Periodic Mesoporous Organosilica with 1,2-bis[3-(triethoxysilylpropyl)ureido] cyclohexane Function via Basic Co-condensation Self-Assembly

2008 ◽  
Vol 8 (7) ◽  
pp. 3532-3538 ◽  
Author(s):  
M. Abdul Wahab ◽  
I. Kim ◽  
C. S. Ha
Keyword(s):  
Pore Size ◽  
Self Assembly ◽  
Pore Wall ◽  
Periodic Mesoporous Organosilica ◽  
Assembly Method ◽  
Pore Size Distributions ◽  
Bet Analysis ◽  
Diffraction Patterns ◽  
Covalently Linked ◽  
Mesoporous Organosilicas

The synthesized bis silylated long alkyl chain containing organosilicate precursor, 1,2-bis(3-(triethoxysilylpropyl)ureido)cyclohexane (BSPUCh) has been used as co-precursor with 1,2-bis (triethoxysilyl)ethane (BTSE) for the preparation of functional periodic mesoporous organosilicas (PMOs) via surfactant-mediated basic co-condensation self-assembly method. The various characterization techniques such as X-ray diffraction patterns (XRD), transmission electron microscope (TEM), N2 adsorption–desorption isotherms (BET), FT-IR, and 13C and 29Si CPMAS NMR spectroscopies were used to characterize the resulting structure of functionalized PMO mesostructures. Results obtained from XRD, TEM, and BET analysis clearly showed that the structural and pore arrangement of the functionalized PMOs were found to be dependent on the used concentration of BSPUCh. The functional PMOs showed well ordered mesophases when BSPUCh concentration was ≤9 wt% in the initial mixtures, whereas higher concentration of the BSPUCh always produced disordered hierarchical mesostructures with bimodal pore size distributions. The incorporation of BSPUCh also reduces the surface area, pore volume, pore size, and pore wall thickness of the functionalized nanostructures, indicating that the BSPUCh is incorporated in the pore channels of the PMOs. The solid-state 13C and 29Si NMR spectra showed that the BSPUCh organosilicate with non-hydrolyzable bridging ligands propylureidocyclohexane has been successfully covalently linked in the framework of the resulting functional PMOs.

Template-directed synthesis of donor/acceptor [2]catenanes and [2]rotaxanes

2008 ◽  
Vol 80 (3) ◽  
pp. 485-506 ◽  
Author(s):  
Kirsten E. Griffiths ◽  
J. Fraser Stoddart
Keyword(s):  
Drug Delivery ◽  
Molecular Electronics ◽  
Statistical Methods ◽  
Great Promise ◽  
Interlocked Molecules ◽  
Directed Synthesis ◽  
Donor Acceptor ◽  
Molecular Compounds

The synthesis of mechanically interlocked molecular compounds has advanced by leaps and bounds since the early days of statistical methods and covalent-directing strategies. Template-directed synthesis has emerged as the method of choice for the construction of increasingly complex and functional [2]catenanes and [2]rotaxanes. In particular, mechanically interlocked molecules employing π-donating and π-accepting recognition units have been produced with remarkable efficiencies and show great promise in technologies as diverse as molecular electronics and drug delivery.

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