Chemically Fueled Assembly of Macrocycles Comprising Multiple Transient Bonds

2019 ◽  
Author(s):  
Mohammad Mosharraf Hossain ◽  
Joshua Atkinson ◽  
Scott Hartley
Keyword(s):  
Covalent Bond ◽  
Dicarboxylic Acids ◽  
Molecular Assembly ◽  
Chemical Systems ◽  
Complex Architectures ◽  
The Creation ◽  
Dynamic Exchange

Dissipative (nonequilibrium) assembly powered by chemical fuels has great potential for the creation of new adaptive chemical systems. However, while molecular assembly at equilibrium is routinely used to prepare complex architectures from polyfunctional monomers, species formed out of equilibrium have, to this point, been structurally very simple. In most examples the fuel simply effects the formation of a single transient covalent bond. Here, we show that chemical fuels can assemble bifunctional components into macrocycles containing multiple transient bonds. Specifically, dicarboxylic acids give aqueous dianhydride macrocycles on treatment with a carbodiimide. The macrocycle is assembled efficiently as a consequence of both fuel-dependent and -independent mechanisms: it undergoes slower decomposition, building up as the fuel recycles the components, and is a favored product of the dynamic exchange of the anhydride bonds. These results create new possibilities for generating structurally sophisticated out-of-equilibrium species.

Chemically Fueled Assembly of Macrocycles Comprising Multiple Transient Bonds

2019 ◽  
Author(s):  
Mohammad Mosharraf Hossain ◽  
Joshua Atkinson ◽  
Scott Hartley
Keyword(s):  
Covalent Bond ◽  
Dicarboxylic Acids ◽  
Molecular Assembly ◽  
Chemical Systems ◽  
Complex Architectures ◽  
The Creation ◽  
Dynamic Exchange

Dissipative (nonequilibrium) assembly powered by chemical fuels has great potential for the creation of new adaptive chemical systems. However, while molecular assembly at equilibrium is routinely used to prepare complex architectures from polyfunctional monomers, species formed out of equilibrium have, to this point, been structurally very simple. In most examples the fuel simply effects the formation of a single transient covalent bond. Here, we show that chemical fuels can assemble bifunctional components into macrocycles containing multiple transient bonds. Specifically, dicarboxylic acids give aqueous dianhydride macrocycles on treatment with a carbodiimide. The macrocycle is assembled efficiently as a consequence of both fuel-dependent and -independent mechanisms: it undergoes slower decomposition, building up as the fuel recycles the components, and is a favored product of the dynamic exchange of the anhydride bonds. These results create new possibilities for generating structurally sophisticated out-of-equilibrium species.

scholarly journals Supramolecular interactions in the solid state

IUCrJ ◽  
2015 ◽  
Vol 2 (6) ◽  
pp. 675-690 ◽  
Author(s):  
Giuseppe Resnati ◽  
Elena Boldyreva ◽  
Petra Bombicz ◽  
Masaki Kawano
Keyword(s):  
Solid State ◽  
Intermolecular Interactions ◽  
Historical Review ◽  
Covalent Bond ◽  
Halogen Bonding ◽  
Molecular Assembly ◽  
Supramolecular Interactions ◽  
Ambient Conditions ◽  
Chemical Research ◽  
Primary Means

In the last few decades, supramolecular chemistry has been at the forefront of chemical research, with the aim of understanding chemistry beyond the covalent bond. Since the long-range periodicity in crystals is a product of the directionally specific short-range intermolecular interactions that are responsible for molecular assembly, analysis of crystalline solids provides a primary means to investigate intermolecular interactions and recognition phenomena. This article discusses some areas of contemporary research involving supramolecular interactions in the solid state. The topics covered are: (1) an overview and historical review of halogen bonding; (2) exploring non-ambient conditions to investigate intermolecular interactions in crystals; (3) the role of intermolecular interactions in morphotropy, being the link between isostructurality and polymorphism; (4) strategic realisation of kinetic coordination polymers by exploiting multi-interactive linker molecules. The discussion touches upon many of the prerequisites for controlled preparation and characterization of crystalline materials.

Axially Chiral Selectors of C2 Symmetry Bound to Silica: Synthesis and HPLC-Evaluation

1995 ◽  
Vol 60 (4) ◽  
pp. 645-658 ◽  
Author(s):  
Miloš Tichý ◽  
Jana Holanová ◽  
Ivo Starý ◽  
Irena G. Stará ◽  
Jiří Závada
Keyword(s):  
Dicarboxylic Acid ◽  
Absolute Configuration ◽  
Stationary Phases ◽  
Covalent Bond ◽  
Dicarboxylic Acids ◽  
The Other ◽  
Chiral Selectors ◽  
Cd Spectrum ◽  
Axially Chiral ◽  
Silica Synthesis

Axially chiral biaryl stationary phases (CSPs) of C2 symmetry bound to 3-aminopropyl silica both by ionic and covalent bond were prepared. The separation effectivity of the CSPs so obtained was investigated using 2-acylamino alcohols and biaryl derivatives as analytes. Whereas ionically bound phases derived from biphenyl-2,2'-dicarboxylic or 2,2'-bipyridine-3,3'-dicarboxylic acids (CSP 1, 2, 3 and 4) generally exhibited good resolving performance for 2-acylamino alcohols, they were ineffective for biaryl derivatives. On the other hand, covalent CSPs showed poor selector properties with acylamino alcohols; the binaphthyl CSP 7 resolved some of the biaryl analytes. Phase CSP 6 was completely inactive toward all the compounds tested. Absolute configuration of 4,4',6,6'-tetranitrobiphenyl-2,2'-dicarboxylic acid (II) has been derived from its CD spectrum and some speculations on configuration of bipyridine diacid IV are presented.

scholarly journals Influence of the Presence of Disulphide Bonds in Aromatic or Aliphatic Dicarboxylic Acid Hardeners Used to Produce Reprocessable Epoxidized Thermosets

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 534
Author(s):  
Chiara Di Mauro ◽  
Alice Mija
Keyword(s):  
Renewable Resources ◽  
Dicarboxylic Acids ◽  
Thermomechanical Properties ◽  
Scanning Calorimetry ◽  
Disulphide Bonds ◽  
Solvent Stability ◽  
Recycling Potential ◽  
Dynamic Exchange ◽  
The Impact ◽  
First Time

The design of polymers from renewable resources with recycling potential comes from economic and environmental problems. This work focused on the impact of disulphide bonds in the dicarboxylic acids reactions with three epoxidized vegetable oils (EVOs). For the first time, the comparison between aromatic vs. aliphatic dicarboxylic acids, containing or not S–S bonds with EVOs was discussed and evaluated by dynamic scanning calorimetry. The obtained thermosets showed reprocessability, by the dual dynamic exchange mechanism. The virgin and reprocessed materials were characterized and the thermomechanical properties were compared. The thermosets derived from EVOs with high epoxy content combined with aromatic diacids containing disulphide bridges showed high glass transition values (~111 °C), high crosslink densities and good solvent stability.

scholarly journals Los procesos de veridicción en «A Very Short Story», de Ernest Hemingway (The Veridiction Processes in “A Very Short Story,” by Ernest Hemingway)

LETRAS ◽  
2017 ◽  
Vol 2 (60) ◽  
pp. 213
Author(s):  
Isabel Cristina Bolaños Villalobos ◽  
Gabriela Cerdas Ramírez ◽  
Jimmy Ramírez Acosta
Keyword(s):  
Short Story ◽  
Cultural Context ◽  
Ernest Hemingway ◽  
Internal Dialogue ◽  
The Creation ◽  
Para Determinar ◽  
Dynamic Exchange ◽  
The Relationship

El estudio desarrolla un análisis de la obra «A Very Short Story», de Ernest Hemingway, desde el punto de vista de lo verosímil. Se efectúa según las propuestas de Todorov, Metz, Jakobson y Matamoro para determinar que esta obra es autobiográfica y que muestra un juego de dinamismo entre el texto y el diálogo interno. Se acude a algunas ideas de Linda Anderson y de Shoshana Felman sobre la autobiografía. Además, se analizan situaciones como la referencialidad y la relación entre la literatura y la realidad, la influencia del contexto histórico y cultural en la lectura de un texto, la interrelación del discurso y la creación de significación y el papel del receptor. This study presents an analysis of the work “A Very Short Story,” by Ernest Hemingway, from the perspective of verisimilitude. Based on the proposals of Todorov, Jakobson, Metz and Matamoro, it can be determined that this story is autobiographical and that a dynamic exchange takes place between the text and the internal dialogue. The ideas of Linda Anderson and Shoshana Felman about autobiography are taken into account. Moreover, issues of referentiality and the relationship between literature and reality, the influence of the historical and cultural context in reading a text, the interplay of discourse and the creation of meaning and the role of the receiver are all analyzed here.

scholarly journals Molecular architectonics of DNA for functional nanoarchitectures

2020 ◽  
Vol 11 ◽  
pp. 124-140 ◽  
Author(s):  
Debasis Ghosh ◽  
Lakshmi P Datta ◽  
Thimmaiah Govindaraju
Keyword(s):  
Structural Engineering ◽  
Structural Characteristics ◽  
Persistence Length ◽  
Dna Nanotechnology ◽  
Functional Materials ◽  
Molecular Assembly ◽  
Structural And Functional Properties ◽  
The Creation ◽  
Functional Dna ◽  
Dna 2

DNA is the key biomolecule central to almost all processes in living organisms. The eccentric idea of utilizing DNA as a material building block in molecular and structural engineering led to the creation of numerous molecular-assembly systems and materials at the nanoscale. The molecular structure of DNA is believed to have evolved over billions of years, with structure and stability optimizations that allow life forms to sustain through the storage and transmission of genetic information with fidelity. The nanoscale structural characteristics of DNA (2 nm thickness and ca. 40–50 nm persistence length) have inspired the creation of numerous functional patterns and architectures through noncovalent conventional and unconventional base pairings as well as through mutual templating-interactions with small organic molecules and metal ions. The recent advancements in structural DNA nanotechnology allowed researchers to design new DNA-based functional materials with chemical and biological properties distinct from their parent components. The modulation of structural and functional properties of hybrid DNA ensembles of small functional molecules (SFMs) and short oligonucleotides by adapting the principles of molecular architectonics enabled the creation of novel DNA nanoarchitectures with potential applications, which has been termed as templated DNA nanotechnology or functional DNA nanoarchitectonics. This review highlights the molecular architectonics-guided design principles and applications of the derived DNA nanoarchitectures. The advantages and ability of functional DNA nanoarchitectonics to overcome the trivial drawbacks of classical DNA nanotechnology to fulfill realistic and practical applications are highlighted, and an outlook on future developments is presented.

Kinetics-dominated structure and stimuli-responsiveness in the assembly of colloidal nanotubes

RSC Advances ◽  
2016 ◽  
Vol 6 (58) ◽  
pp. 52950-52956 ◽  
Author(s):  
Kazuhiro Shikinaka ◽  
Saori Mori ◽  
Kiyotaka Shigehara ◽  
Hiroyasu Masunaga ◽  
Takamasa Sakai
Keyword(s):  
Dicarboxylic Acids ◽  
Molecular Assembly ◽  
Stimuli Responsive ◽  
Assembly Kinetics ◽  
Rigid Rod ◽  
Responsive Hydrogels ◽  
Kinetics Of

In this paper, we discuss the molecular assembly kinetics of stimuli-responsive hydrogels prepared from imogolite, which is a rigid rod-like colloidal inorganic nanotube, and dicarboxylic acids.

The role of affect in feelings of obligation

2020 ◽  
Vol 43 ◽  
Author(s):  
Stefen Beeler-Duden ◽  
Meltem Yucel ◽  
Amrisha Vaish
Keyword(s):  
Positive Emotions ◽  
The Creation ◽  
Sense Of Obligation

Abstract Tomasello offers a compelling account of the emergence of humans’ sense of obligation. We suggest that more needs to be said about the role of affect in the creation of obligations. We also argue that positive emotions such as gratitude evolved to encourage individuals to fulfill cooperative obligations without the negative quality that Tomasello proposes is inherent in obligations.

Aldehyde gold clusters for molecular labeling

1995 ◽  
Vol 53 ◽  
pp. 858-859
Author(s):  
James F. Hainfeld ◽  
Frederic R. Furuya
Keyword(s):  
Covalent Bond ◽  
Aldehyde Group ◽  
Gold Clusters ◽  
Side Reactions ◽  
Amino Groups ◽  
Sodium Cyanoborohydride ◽  
Schiff’S Base ◽  
Protein Molecules ◽  
Hydroxysuccinimide Esters ◽  
Primary Amino

Glutaraldehyde is a useful tissue and molecular fixing reagents. The aldehyde moiety reacts mainly with primary amino groups to form a Schiff's base, which is reversible but reasonably stable at pH 7; a stable covalent bond may be formed by reduction with, e.g., sodium cyanoborohydride (Fig. 1). The bifunctional glutaraldehyde, (CHO-(CH2)3-CHO), successfully stabilizes protein molecules due to generally plentiful amines on their surface; bovine serum albumin has 60; 59 lysines + 1 α-amino. With some enzymes, catalytic activity after fixing is preserved; with respect to antigens, glutaraldehyde treatment can compromise their recognition by antibodies in some cases. Complicating the chemistry somewhat are the reported side reactions, where glutaraldehyde reacts with other amino acid side chains, cysteine, histidine, and tyrosine. It has also been reported that glutaraldehyde can polymerize in aqueous solution. Newer crosslinkers have been found that are more specific for the amino group, such as the N-hydroxysuccinimide esters, and are commonly preferred for forming conjugates. However, most of these linkers hydrolyze in solution, so that the activity is lost over several hours, whereas the aldehyde group is stable in solution, and may have an advantage of overall efficiency.

Structure of stacking faults in pyrite using TEM techniques

1992 ◽  
Vol 50 (1) ◽  
pp. 358-359
Author(s):  
Raja Subramanian ◽  
Kenneth S. Vecchio
Keyword(s):  
Lattice Structure ◽  
Stacking Faults ◽  
Covalent Bond ◽  
Group Symmetry ◽  
Iron Pyrite ◽  
Dislocation Glide ◽  
Partial Dislocations ◽  
Transmission Electron ◽  
Contrast Analysis ◽  
Chlorine Ions

The structure of stacking faults and partial dislocations in iron pyrite (FeS2) have been studied using transmission electron microscopy. Pyrite has the NaCl structure in which the sodium ions are replaced by iron and chlorine ions by covalently-bonded pairs of sulfur ions. These sulfur pairs are oriented along the <111> direction. This covalent bond between sulfur atoms is the strongest bond in pyrite with Pa3 space group symmetry. These sulfur pairs are believed to move as a whole during dislocation glide. The lattice structure across these stacking faults is of interest as the presence of these stacking faults has been preliminarily linked to a higher sulfur reactivity in pyrite. Conventional TEM contrast analysis and high resolution lattice imaging of the faulted area in the TEM specimen has been carried out.

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