scholarly journals Taming nitroformate through encapsulation with nitrogen-rich hydrogen-bonded organic frameworks

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jichuan Zhang ◽  
Yongan Feng ◽  
Richard J. Staples ◽  
Jiaheng Zhang ◽  
Jean’ne M. Shreeve
Keyword(s):  
Thermal Stability ◽  
Hydrogen Bonds ◽  
Self Assembly ◽  
Energetic Materials ◽  
Decomposition Temperature ◽  
High Oxygen Content ◽  
The Poor ◽  
Simple Preparation ◽  
First Time ◽  
Hydrogen Bonded

AbstractOwing to its simple preparation and high oxygen content, nitroformate [−C(NO2)3, NF] is an extremely attractive oxidant component for propellants and explosives. However, the poor thermostability of NF-based derivatives has been an unconquerable barrier for more than 150 years, thus hindering its application. In this study, the first example of a nitrogen-rich hydrogen-bonded organic framework (HOF-NF) is designed and constructed through self-assembly in energetic materials, in which NF anions are trapped in pores of the resulting framework via the dual force of ionic and hydrogen bonds from the strengthened framework. These factors lead to the decomposition temperature of the resulting HOF-NF moiety being 200 °C, which exceeds the challenge of thermal stability over 180 °C for the first time among NF-based compounds. A large number of NF-based compounds with high stabilities and excellent properties can be designed and synthesized on the basis of this work.

Hydrogen-bonded Supramolecular Solids of Resorcinarenes with 4,4´-Bipyridine and 1,4-Bis(4-pyridyl)butadiyne

2008 ◽  
Vol 63 (8) ◽  
pp. 945-953 ◽  
Author(s):  
Xiao-Ling Wang ◽  
Shu-Qun Liu ◽  
Qian-Feng Zhang
Keyword(s):  
Hydrogen Bonds ◽  
Self Assembly ◽  
Ethanol Solution ◽  
The Self ◽  
Acetonitrile Solution ◽  
Chain Polymer ◽  
Extended Cavity ◽  
Hydrogen Bonded

The self-assembly of the bifunctional 4,4'-bipyridine (bipy) with bowl-shaped C-iso-butylresorcinarene (1) under two different conditions was investigated. The 0D carcerand-like capsule complex 1 · 2(bipy) · 0.5EtOH · 4H2O (3) with four stacked bipys was formed in 95% ethanol solution. The 2D wave-like layered sheet complex 1 · 2(bipy) ·CH3CN · 2H2O (4) constructed by bipy bridging 1D wave-like ribbons with hydrogen-bonded planar hexagonal rings was obtained from a wet acetonitrile solution. The multicomponent complexes 2 · 2(bpb) · MeCN (5) and 1 · (bpb) · 2MeOH (6) formed from self-assembly of 1,4-bis(4-pyridyl)butadiyne (bpb) with Cmethyl- resorcinarene (2) in acetonitrile and 1 in methanol, respectively. The structure of 5 reveals four symmetrical intermolecular O-H···N hydrogen bonds between 2 and bpb with two slightly distorted pyridine molecules, forming a wave-like chain polymer. A large extended cavity is built up to give a multicomponent molecular host which is filled with a solvent- and self-inclusion molecule as guests. The structure of 6 exhibits a pair of resorcinarene molecules side-connected to each other by two intermolecular O-H···O hydrogen bonds to form a 1D wave-like tape, which is further bridged by bpb with two perpendicular pyridines to form a 2D sheet.

scholarly journals Development of Interfacial Adhesive Property by Novel Anti-Stripping Composite between Acidic Aggregate and Asphalt

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 473
Author(s):  
Guohong Zhang ◽  
Jianhui Qiu ◽  
Jingzhuo Zhao ◽  
Dingbang Wei ◽  
Hui Wang
Keyword(s):  
Thermal Stability ◽  
Interfacial Adhesion ◽  
Moisture Damage ◽  
Decomposition Temperature ◽  
Social Significance ◽  
Excellent Thermal Stability ◽  
Adhesion Properties ◽  
Stability Performance ◽  
The Poor ◽  
Damage Process

Studies on control of and preventive measures against asphalt pavement moisture damage have important economic and social significance due to the multiple damage and repair of pavements, the reasons for which include the poor interfacial adhesive ability between acidic aggregates and asphalts. Anti-stripping agent is used in order to improve the poor adhesion, and decomposition temperature is regarded as being important for lots of anti-stripping products, because they always decompose and lose their abilities under the high temperature in the mixing plant before application to the pavement. A novel anti-stripping composite, montmorillonoid/Polyamide (OMMT/PAR), which possesses excellent thermal stability performance and is effective in preventing moisture damage, especially for acidic aggregates, was prepared. Moreover, the modification mechanisms and pavement properties were also investigated with reference to the composites. The results show that OMMT/PAR was prepared successfully, improving the interfacial adhesion between the acidic aggregate and the modified asphalt. Due to the nanostructure of OMMT/PAR, the thermal stability was enhanced dramatically and the interfacial adhesion properties were also improved. Furthermore, asphalts modified with OMMT/PAR and their mixtures showed excellent properties. Finally, the moisture damage process and the mechanisms by which OMMT/PAR improves the interfacial adhesion properties are explained through adhesion mechanism analyses.

scholarly journals Coordination-Bond-Directed Synthesis of Hydrogen-bonded Organic Frameworks from Metal–Organic Frameworks as Templates

2021 ◽  
Author(s):  
Jian Su ◽  
Shuai Yuan ◽  
Yi-Xun Cheng ◽  
Zhi-Mei Yang ◽  
Jing-Lin Zuo
Keyword(s):  
Hydrogen Bonds ◽  
Self Assembly ◽  
Metal Organic Frameworks ◽  
Coordination Bond ◽  
The Self ◽  
Controlled Synthesis ◽  
Weak Hydrogen Bonds ◽  
Directed Synthesis ◽  
Metal Organic ◽  
Hydrogen Bonded

Controlled synthesis of hydrogen-bonded organic frameworks (HOFs) remains challenging, because the self-assembly of ligands is not only directed by weak hydrogen bonds, but also affected by other competing van der...

scholarly journals Nitro-, Cyano-, and Methylfuroxans, and Their Bis-Derivatives: From Green Primary to Melt-Cast Explosives

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5836
Author(s):  
Alexander A. Larin ◽  
Dmitry M. Bystrov ◽  
Leonid L. Fershtat ◽  
Alexey A. Konnov ◽  
Nina N. Makhova ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Energetic Materials ◽  
Decomposition Temperature ◽  
Pentaerythritol Tetranitrate ◽  
Mechanical Stimuli ◽  
Mechanical Sensitivity ◽  
Isodesmic Reactions ◽  
Formation Enthalpies ◽  
Methyl Derivatives ◽  
Derivatives Of

In the present work, we studied in detail the thermochemistry, thermal stability, mechanical sensitivity, and detonation performance for 20 nitro-, cyano-, and methyl derivatives of 1,2,5-oxadiazole-2-oxide (furoxan), along with their bis-derivatives. For all species studied, we also determined the reliable values of the gas-phase formation enthalpies using highly accurate multilevel procedures W2-F12 and/or W1-F12 in conjunction with the atomization energy approach and isodesmic reactions with the domain-based local pair natural orbital (DLPNO) modifications of the coupled-cluster techniques. Apart from this, we proposed reliable benchmark values of the formation enthalpies of furoxan and a number of its (azo)bis-derivatives. Additionally, we reported the previously unknown crystal structure of 3-cyano-4-nitrofuroxan. Among the monocyclic compounds, 3-nitro-4-cyclopropyl and dicyano derivatives of furoxan outperformed trinitrotoluene, a benchmark melt-cast explosive, exhibited decent thermal stability (decomposition temperature >200 °C) and insensitivity to mechanical stimuli while having notable volatility and low melting points. In turn, 4,4′-azobis-dicarbamoyl furoxan is proposed as a substitute of pentaerythritol tetranitrate, a benchmark brisant high explosive. Finally, the application prospects of 3,3′-azobis-dinitro furoxan, one of the most powerful energetic materials synthesized up to date, are limited due to the tremendously high mechanical sensitivity of this compound. Overall, the investigated derivatives of furoxan comprise multipurpose green energetic materials, including primary, secondary, melt-cast, low-sensitive explosives, and an energetic liquid.

THERMAL STABILITY AND COMBUSTION BEHAVIORS OF ENERGETIC MATERIALS BASED ON A NEW HETEROCYCLE AZASYDNONE

2018 ◽  
Vol 17 (2) ◽  
pp. 147-170 ◽  
Author(s):  
Valery V. Serushkin ◽  
Valery P. Sinditskii ◽  
Sergey A. Filatov ◽  
P. D. Kulagina ◽  
V. T. Nguyen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Energetic Materials ◽  
Combustion Behaviors

Dissolution and Performing Homogeneous Photocatalysis of Polymeric Carbon Nitride

2018 ◽  
Author(s):  
Chaofeng Huang ◽  
Jing Wen ◽  
Yanfei Shen ◽  
Fei He ◽  
Li Mi ◽  
...  
Keyword(s):  
Conjugated Polymer ◽  
Carbon Nitride ◽  
Heterogeneous Catalysts ◽  
Methane Sulfonic Acid ◽  
Environment Friendly ◽  
The Poor ◽  
Catalytic Sites ◽  
Homogeneous Photocatalysis ◽  
Polymeric Carbon ◽  
First Time

<a></a><a>As a metal-free conjugated polymer, carbon nitride (CN) has attracted tremendous attention as heterogeneous (photo)catalysts. </a><a></a><a>By following prototype of enzymes, making all catalytic sites of accessible via homogeneous reactions is a promising approach toward maximizing CN activity, but hindered due to </a><a></a><a>the poor insolubility of CN</a>. Herein, we report the dissolution of CN in environment-friendly methane sulfonic acid and the homogeneous photocatalysis driven by CN for the first time with the activity boosted up to 10-times, comparing to the heterogeneous counterparts. Moreover, facile recycling and reusability, the <a>hallmark</a> of heterogeneous catalysts, were kept for the homogeneous CN photocatalyst via reversible precipitation using poor solvents. It opens new vista of CN in homogeneous catalysis and offers a successful example of polymeric catalysts in bridging gaps of homo/heterogeneous catalysis.

Single Amino Acid Based Self-Assemblies of Cysteine and Methionine

2018 ◽  
Author(s):  
Nidhi Gour ◽  
Bharti Koshti ◽  
Chandra Kanth P. ◽  
Dhruvi Shah ◽  
Vivek Shinh Kshatriya ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Self Assembly ◽  
Aromatic Amino Acids ◽  
Neutral Condition ◽  
Single Amino Acid ◽  
Binding Assays ◽  
Human Neuroblastoma ◽  
Cytotoxicity Assays ◽  
First Time

We report for the very first time self-assembly of Cysteine and Methionine to discrenible strucutres under neutral condition. To get insights into the structure formation, thioflavin T and Congo red binding assays were done which revealed that aggregates may not have amyloid like characteristics. The nature of interactions which lead to such self-assemblies was purported by coincubating assemblies in urea and mercaptoethanol. Further interaction of aggregates with short amyloidogenic dipeptide diphenylalanine (FF) was assessed. While cysteine aggregates completely disrupted FF fibres, methionine albeit triggered fibrillation. The cytotoxicity assays of cysteine and methionine structures were performed on Human Neuroblastoma IMR-32 cells which suggested that aggregates are not cytotoxic in nature and thus, may not have amyloid like etiology. The results presented in the manuscript are striking, since to the best of our knowledge,this is the first report which demonstrates that even non-aromatic amino acids (cysteine and methionine) can undergo spontaneous self-assembly to form ordered aggregates.

Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

2018 ◽  
Author(s):  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Rachel Evans
Keyword(s):  
Real Time ◽  
Absorption Spectroscopy ◽  
Self Assembly ◽  
Uv Light ◽  
Wormlike Micelles ◽  
Tetraethylene Glycol ◽  
Light Illumination ◽  
First Time ◽  
Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such as<i></i>drug delivery and micellar catalysis. Currently, their behaviour in the equilibrium <i>cis-</i>and <i>trans</i>-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>) using small-angle neutron scattering (SANS). We show that the incorporation of <i>in-situ</i>UV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>could switch between wormlike micelles (<i>trans</i>native state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked <i>in</i><i>-situ</i>through combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

scholarly journals First thermal studies on visible-light-switchable negative T-type photochromes of a nitrile-rich series

RSC Advances ◽  
2021 ◽  
Vol 11 (34) ◽  
pp. 21097-21103
Author(s):  
Mikhail Yu. Belikov ◽  
Mikhail Yu. Ievlev
Keyword(s):  
Thermal Stability ◽  
Visible Light ◽  
Temperature Effect ◽  
Thermal Studies ◽  
First Time ◽  
Thermal Stability Of

The temperature effect on the thermal stability of both the initial and photoinduced forms of nitrile-rich T-type photochromes was studied for the first time.

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