Academic literature on the topic 'Covalent Interactions'

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Journal articles on the topic "Covalent Interactions"

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Alkorta, Ibon, and Sławomir J. Grabowski. "Non-covalent interactions." Computational and Theoretical Chemistry 998 (October 2012): 1. http://dx.doi.org/10.1016/j.comptc.2012.07.025.

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FINKELSTEIN, ALEXEI V., MICHAEL Y. LOBANOV, NIKITA V. DOVIDCHENKO, and NATALIA S. BOGATYREVA. "MANY-ATOM VAN DER WAALS INTERACTIONS LEAD TO DIRECTION-SENSITIVE INTERACTIONS OF COVALENT BONDS." Journal of Bioinformatics and Computational Biology 06, no. 04 (August 2008): 693–707. http://dx.doi.org/10.1142/s0219720008003606.

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Strict physical theory and numerical calculations show that a specific coupling of many-atom van der Waals interactions with covalent bonding can significantly (half as much) increase the strength of attractive dispersion interactions when the direction of interaction coincides with the direction of the covalent bond, and decrease this strength when the direction of interaction is perpendicular to the direction of the covalent bond. The energy effect is comparable to that caused by the replacement of atoms (e.g. N by C or O ) in conventional pairwise van der Waals interactions. Analysis of protein structures shows that they bear an imprint of this effect. This means that many-atom van der Waals interactions cannot be ignored in refinement of protein structures, in simulations of their folding, and in prediction of their binding affinities.
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Bagus, Paul S., and Connie J. Nelin. "Covalent interactions in oxides." Journal of Electron Spectroscopy and Related Phenomena 194 (June 2014): 37–44. http://dx.doi.org/10.1016/j.elspec.2013.11.004.

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Schneider, Hans-J�rg. "EDITORIAL: NON-COVALENT INTERACTIONS." Journal of Physical Organic Chemistry 10, no. 5 (May 1997): 253. http://dx.doi.org/10.1002/(sici)1099-1395(199705)10:5<253::aid-poc1875>3.0.co;2-r.

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Olson, R. E. "Ionic-covalent collision interactions." International Journal of Quantum Chemistry 24, S17 (July 9, 2009): 49–64. http://dx.doi.org/10.1002/qua.560240807.

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Majumdar, Dhrubajyoti, A. Frontera, Rosa M. Gomila, Sourav Das, and Kalipada Bankura. "Synthesis, spectroscopic findings and crystal engineering of Pb(ii)–Salen coordination polymers, and supramolecular architectures engineered by σ-hole/spodium/tetrel bonds: a combined experimental and theoretical investigation." RSC Advances 12, no. 10 (2022): 6352–63. http://dx.doi.org/10.1039/d1ra09346k.

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We report σ-hole interaction/spodium/tetrel bonding and other non-covalent interactions in a heteronuclear Pb(ii)–Salen coordination polymer using DFT, HSA, QTAIM/NCI, and QTAIM/ELF plots. The non-covalent interactions predominantly drive the formation of extended architectures.
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Bjij, Imane, Pritika Ramharack, Shama Khan, Driss Cherqaoui, and Mahmoud E. S. Soliman. "Tracing Potential Covalent Inhibitors of an E3 Ubiquitin Ligase through Target-Focused Modelling." Molecules 24, no. 17 (August 28, 2019): 3125. http://dx.doi.org/10.3390/molecules24173125.

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The Nedd4-1 E3 Ubiquitin ligase has been implicated in multiple disease conditions due its overexpression. Although the enzyme may be targeted both covalently and non-covalently, minimal studies provide effective inhibitors against it. Recently, research has focused on covalent inhibitors based on their characteristic, highly-selective warheads and ability to prevent drug resistance. This prompted us to screen for new covalent inhibitors of Nedd4-1 using a combination of computational approaches. However, this task proved challenging due to the limited number of electrophilic moieties available in virtual libraries. Therefore, we opted to divide an existing covalent Nedd4-1 inhibitor into two parts: a non-covalent binding group and a pre-selected α, β-unsaturated ester that forms the covalent linkage with the protein. A non-covalent pharmacophore model was built based on molecular interactions at the binding site. The pharmacophore was then subjected to virtual screening to identify structurally similar hit compounds. Multiple filtrations were implemented prior to selecting four hits, which were validated with a covalent conjugation and later assessed by molecular dynamic simulations. The results showed that, of the four hit molecules, Zinc00937975 exhibited advantageous molecular groups, allowing for favourable interactions with one of the characteristic cysteine residues. Predictive pharmacokinetic analysis further justified the compound as a potential lead molecule, prompting its recommendation for confirmatory biological evaluation. Our inhouse, refined, pharmacophore model approach serves as a robust method that will encourage screening for novel covalent inhibitors in drug discovery.
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Novikov, Alexander S. "Non-Covalent Interactions in Polymers." Polymers 15, no. 5 (February 24, 2023): 1139. http://dx.doi.org/10.3390/polym15051139.

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Non-covalent interactions are one of the key topics in modern chemical science. These inter- and intramolecular weak interactions (e.g., hydrogen, halogen, and chalcogen bonds, stacking interactions and metallophilic contacts) have a significant effect on the properties of polymers. In this Special Issue, “Non-covalent interactions in polymers”, we tried to collect fundamental and applied research manuscripts (original research articles and comprehensive review papers) focused on non-covalent interactions in polymer chemistry and related fields. The scope of the Special Issue is very broad: we welcome all the contributions that deal with the synthesis, structure, functionality and properties of polymer systems involving non-covalent interactions.
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Wang, Zhifang, Geng An, Ye Zhu, Xuemin Liu, Yunhua Chen, Hongkai Wu, Yingjun Wang, Xuetao Shi, and Chuanbin Mao. "3D-printable self-healing and mechanically reinforced hydrogels with host–guest non-covalent interactions integrated into covalently linked networks." Materials Horizons 6, no. 4 (2019): 733–42. http://dx.doi.org/10.1039/c8mh01208c.

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Černý, Jiří, and Pavel Hobza. "Non-covalent interactions in biomacromolecules." Physical Chemistry Chemical Physics 9, no. 39 (2007): 5291. http://dx.doi.org/10.1039/b704781a.

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Dissertations / Theses on the topic "Covalent Interactions"

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Yang, Lixu. "Non-covalent interactions in solution." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/8097.

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Non-covalent interactions taking place in solution are essential in chemical and biological systems. The solvent environment plays an important role in determining the geometry and stability of interactions. This thesis examines aromatic stacking interactions, alkyl-alkyl interactions, edge-to-face aromatic interactions, halogen bonds and hydrogen…hydrogen interactions in solution. Chapter 1 briefly introduces the different classes of non-covalent interactions, in addition to the state-of-the-art models and methods for investigating these weak interactions. The chapter finishes with a focus on dispersion interaction in alkanes and arenes. Chapter 2 investigates dispersion interactions between stacked aromatics in solution using a new class of complexes and thermodynamic double mutant cycles (DMCs). In extended aromatics, dispersion was detected as providing a small but significant contribution to the overall stacking free energies. Chapter 3 concerns the experimental measurement of alkyl-alkyl dispersion interactions in a wide range of solvents using Wilcox torsion balances. The contribution of dispersion interactions to alkyl-alkyl association was shown to be very small, with DMC, QSPR method and Hunter's solvation model. Chapter 4 studies edge-to-face aromatic interactions in series of solvents. In the open system, edge-to-face aromatic interactions were found to be sensitive to the solvent environment. The solvent effects were complicated and cannot be rationalised by a single parameter. Further analysis is needed. Chapter 5 describes a preliminary approach to investigate organic halogen…π interactions in solution using supramolecular complexes and torsion balances. Chapter 6 is a preliminary investigation of the ability of hydrogen atoms to act as H bond acceptors in silane compounds. Computations and 1H NMR demonstrated a weak interaction between silane and perfluoro-tert-butanol.
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Cockroft, Scott L. "Understanding non-covalent interactions." Thesis, University of Sheffield, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434497.

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Bayach, Imene. "Non-covalent interactions in natural products." Thesis, Limoges, 2014. http://www.theses.fr/2014LIMO0050/document.

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Les polyphénols naturels forment des complexes non-covalents dans lesquels le π-stacking et les liaisons hydrogène jouent un rôle clé dans la stabilisation. Les calculs DFT incluant la dispersion (DFT-D), la description des processus d'agrégation non-covalente de produits naturels devient fiable. Dans ce travail, les méthodes DFT-D sont appliquées à i) la compréhension de la biosynthèse stéréo- et régio-sélective des oligostilbenoïdes, ii) la prédiction de l'agrégation des antioxydants naturels au sein de la membrane bicouche lipidique, qui pourrait rationaliser la synergie de la vitamine E, la vitamine C et polyphénols dans leur action antioxydante, et iii) la modulation des propriétés optiques de dérivés de chalcones
Natural polyphenols form non-covalent complexes in which π-stacking and H-bonding play a key stabilizing role. The dispersion-corrected DFT calculations have paved the way towards reliable description of aggregation processes of natural products. In this work, these methods are applied at i) understanding of stereo- and regio-selective oligostilbenoids biosynthesis; ii) predicting natural antioxidant aggregation within lipid bilayer membrane, which may allow rationalizing the synergism of vitamin E, vitamin C and polyphenols in their antioxidant action; and iii) modulating optical properties of chalcone derivatives
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Hubbard, Thomas A. "Non-covalent interactions in lubricant chemistry." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/15935.

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Lubricant formulations are highly complex mixtures, containing a multitude of additives, each geared towards improving the efficiency of often highly specialised processes. The study of lubrication, or tribology, is a huge area of research, but is often overlooked by chemists in favour of pharmaceutical or agrochemical research. This thesis lays the foundation for the study and further understanding of additive-additive interactions in a lubricant formulation. Chapter one presents a concise introduction to modern lubricant formulations by providing a historical background and examining current understanding, while focusing not on the more widely publicised engineering aspects, but on the chemical properties and mechanisms of lubricant formulations. In order to dissect out additive-additive interactions from additive-solvent interactions, a study of the biggest single component in any lubricant formulation, the base oil, is performed in Chapter two. By using a series of molecular torsion balances which have been shown to be heavily influenced by solvent effects, it is revealed that the complex multitude of available commercial base oils can be substituted with a single common lab solvent. In Chapter three, a computational reparameterisation and experimental examination of previous semi-empirical models for the prediction of hydrogen-bond energies in solution using electrostatic surface potentials was performed. Surprisingly, it was found that a simple DFT/B3LYP/6-31G* method provides a better prediction of H-bond energies in solution than more complex models or functional-group corrected methods. Chapter four focuses on the fundamental understanding of entropy and conformational flexibility of compounds in solution. Using a simple flexible experimental system, which is capable for forming an internal hydrogen bond in solution, the impact of intramolecular hydrogen bonding on the stability of an intermolecular process was studied using both experimental and computational (DFT/molecular dynamics) methods. A distinct cut-off point was observed experimentally where the intramolecular process is completely out-competed by the intermolecular interaction. A computational model which reproduces the experimental trends has yet to be found.
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SIRTORI, F. RICCARDI. "STUDY OF COVALENT AND NON COVALENT INTERACTIONS OF BIOPOLYMER BY MASS SPECTROMETRY." Doctoral thesis, Università degli Studi di Milano, 2010. http://hdl.handle.net/2434/150205.

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ESI-MS screening methods directly detect ligand-target non covalent complexes in the gas phase and allow inference of affinity (and specificity) of the ligand-target interaction in solution [1, 2]. The identity of different complexes can be directly assessed as the mass of each molecule works as intrinsic label. Biopolymers can be screened either as a single component or a mixture of different targets; in this way it is possible to determine the selectivity of a new chemical entity for different targets. On the other hand, using ESI-MS it is also possible to identify, within a mixture, components that selectively bind the active site of a certain biopolymer and could be profitably used to screen libraries of known compounds. The aim of this PhD project was the study by ESI mass spectrometry of different noncovalent complexes formed with biopolymers identified as possible therapeutic targets (Mismatch Repair Mechanism and Hsp90). The noncovalent interaction between biological targets and possible ligands were studied in order to identify potential inhibitors. The binding affinities determined by ESI-MS were compared to existing data obtained by solution phase methods. A novel MS-based method was implemented for testing different biopolymer, of therapeutic interest, against a library of fragments (molecular weight 100-300 Da) constituted of about 2,000 compounds. Particularly this approach was used for the identification of new molecules able to recognize TG mismatched base pairs in DNA that are responsible for most of the common mutations leading to formation of tumors in humans. TG mismatches are particularly abundant in cells lacking mismatch repair mechanism (MMR). MMR is involved in the correction of DNA polymerase errors that escape proofreading activity. MMR deficiency increases 50-1000-fold spontaneous mutation rates (microsatellite instability MSI) and in addition, MMR deficiency can lead to resistance to several chemotherapeutic agents (DNA damaging agent) [3]. An ESI-MS method was used to study the complexes formed between different DNA duplexes and minor groove binders and intercalator compounds. A hairpin DNA sequence (CTGGsm) bearing a single T:G mismatch and a matched hairpin DNA sequence (CCGG) were prepared and used to set up the method. Two DNA sequences were also synthesized: a self complementary G:C rich DNA sequence (HFM) and a polyAT DNA duplex (A5TG). The association constants (KAs) were directly determined from the MS spectrum and the amount of bound ligand was used to determine the selectivity of a binder among the different DNA sequences. Minor groove binders confirmed their selectivity toward AT rich DNA duplex (A5TG) whereas a tris imidazole lexitropsin derivative proved to be selective for the TG mismatched DNA hairpin (CTGGsm) in agreement with NMR, SPR, and ITC studies. A medium throughput screening (MTS) method was setup for the screening of the fragment library (about 1,000 cps) and the procedure was validated studying the interactions between the two different DNA sequences (HFM and CTGGsm) and minor groove binders. The screening was performed on the fragment library and hit compounds were afterwards tested against HFM and CCGG in order to identify selective ligands. Among the different hits identified, a slight selectivity (1.3) for the single mismatched sequence was highlighted for the fragment FBA-05-094. Twenty close analogues of FBA-05-094 were subsequently tested against CTGGsm and CCGG DNA with the aim to find more selective and higher affinity ligands. The screening of the fragment library on CTGGsm was repeated using ligand mixtures (5 and 10 components) in order to improve the assay throughput. A good agreement between the results obtained by screening the compounds as single component and in mixture was found. We investigated also the binding of small molecules towards two enzymes (PKA and Hsp90) in order to verify the possibility to apply this procedure to protein targets. Hsp90 (heat shock protein 90) is a molecular chaperone and is one of the most abundant proteins expressed in cell [4]. Targeting Hsp90 with drugs has shown promising effects in clinical trials. Inhibition of the Hsp90 ATPase machinery by natural, semi- and totally synthetic inhibitors has shown promising results in clinic. The interactions between Hsp90 and different known ligands that bind either at N or C terminal binding domains were studied and the dissociation constants for this set of ligands (KD from 0.0007 uM to 103 uM) were previously determined by fluorescence polarization (FP). We found a good agreement between these values and the percentage of bound protein determined by mass spectrometry. A screening of the fragment library against Hsp90 was performed and the resulted hit compounds were compared to those obtained by using NMR FAXS technique[5]. A good correlation was found between the data obtained by MS and NMR screenings. Competition experiments using a known ATP competitor were performed and these studies highlighted the presence of a few ATP competitor ligands in agreement with X-ray experiments. [1] Ganem B, Li Y.-T., Henion JD. Detection of noncovalent Receptor-Ligand complexes by Mass Spectrometry. Journal of American Society for Mass Spectrometry, 113, 6294-6296 (1991) [2] Hofstadler SA, Sannes-Lowery KA. Applications of ESI-MS in drug discovery: interrogation of noncovalent complexes. Nature Reviews Drug Discovery, 5(7), 585-595 (2006) [3] Stojic L., Brun R., Jiricny J., Mismatch repair and DNA damage signalling. DNA Repair, 3, 1091-1101 (2004). [4] Chaudhury S., Welch T.R., Blagg B.S., Hsp90 as a Target for Drug Development. ChemMedChem, 1331-1340 (2006). [5] Dalvit C., Fagerness P.E., Hadden D.T.A., Sarver R.W., Stockman B.J. Fluorine-NMR Experiments for High-Throughput Screening: Theoretical Aspects, Practical Considerations, and Range of Applicability. Journal of American Society for Mass Spectrometry, 125, 7696-7703 (2003)
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Comí, Bonachí Marc. "Biobased polyurethanes with tunable properties through covalent and non-covalent approaches." Doctoral thesis, Universitat Rovira i Virgili, 2017. http://hdl.handle.net/10803/454764.

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Aquesta tesi va dirigida específicament al desenvolupament de poliuretans (PU)s funcionalitzats en la cadena lateral (FPU)s, sintetitzats a partir de diols funcionals que provenen d’àcids grassos i dos diisocianats diferents: el diisocianat d’isoforona (IPDI) i el diisocianat d’hexametilé (HDI). Aquests nous FPUs presenten una amina terciària i grups alquil, al•lil, propargil o la combinació d'aquests en la cadena lateral. Posteriorment els FPUs es modifiquen mitjançant dos mecanismes de post-polimerització basats en enllaços covalents o en enllaços no covalents.En el primer cas, es duen a terme una sèrie de reaccions fotoiniciades d’acoplament tiol-é/í entre el grup al.lil i propargil que presenten els FPUs (formats a partir de IPDI), i tioglicerol. Els hidroxi-PUs obtinguts, exhibeixen una millora del seu caràcter hidrofílic. Alternativament, els FPUs que contenen només una amina terciaria com a grup funcional situat a la cadena lateral del PU, es barregen amb diferents àcids carboxílics per donar una reacció àcid base. Els supramoleculars PUs resultants (SPU)s es caracteritzen per espectroscòpia per a verificar la presència d'enllaços iònics d'hidrogen que uneixen les cadenes de PU mitjançant interaccions fisiques. A més, es demostra la correlació existent entre l'estructura química i les propietats tèrmiques i mecàniques dels materials sintetitzats. Aquests materials presenten prometedores propietats adaptatives. Per exemple, ressalten les bones propietats de regeneració i reciclatge/remodelació, degudes al caràcter reversible de les interaccions físiques. Addicionalment, aquests elastòmers posseeixen una inherent capacitat d’autoreparació, que en termes pràctics es podria veure com una millomillora de la seva sostenibilitat. Finalment, es sintetitzen xarxes de PU que tenen un doble caràcter estructural mitjançant enllaços iònics d'hidrogen dinàmics i entrecreuaments covalents. La variació de la densitat d’entrecreuament covalent introduït per a cada una d’aquestes xarxes, produeixun ajustament sistemàtic de les propietats mecàniques i de la sensibilitat del material a la calor. Aquesta preparació demostra una via simple i eficaç per a la fabricació de poliuretans multifuncionals i l’estratègia seguida també es pot estendre a l'exploració d'altres tipus d'interaccions covalents i no covalents en polímers
Esta tesis está dirigida específicamente al desarrollo de poliuretanos (PU)s funcionalizados en la cadena lateral (FPU)s, sintetizados a partir de dioles funcionales que provienen de ácidos grasos y dos diisocianats diferentes; el diisocianato de isoforona (IPDI) y el diisocianato de hexametileno (HDI). Estos nuevos FPUs presentan una amina terciaria y grupos alquilo, alilo, propargilo o la combinación de éstos en posiciones de cadena lateral. Posteriormente los FPUs se modifican mediante dos mecanismos de post-polimerización basados en enlaces covalentes o en enlaces no covalentes.En el primer caso, se llevan a cabo una serie de reacciones fotoiniciadas de acoplamiento tiol-eno/ino entre el grupo alilo y propargilo que presentan los FPUs (formados a partir de IPDI), y tioglicerol. Los hidroxi-PUs obtenidos, exhiben una mejora de su carácter hidrófilo. Alternativamente, los FPUs que contienen sólo una amina terciaria como grupo funcional situado en la cadena lateral del PU, se mezclan con diferentes ácidos carboxílicos mediante una reacción de ácido base. Los PUs supramoleculares resultantes (SPU)s se caracterizan por espectroscopia para verificar la presencia de enlaces iónicos de hidrógeno que unen las cadenas de PU formando interacciones físicas. Además, se demuestra la correlación existente entre la estructura química y las propiedades térmicas y mecánicas de los materiales sintetizados. Estos materiales presentan prometedoras propiedades adaptativas. Por ejemplo, resaltan las buenas propiedades de regeneración y reciclaje/remodelación, debidas al carácter reversible de las interacciones físicas. Adicionalmente, estos elastómeros poseen una inherente capacidad de autorautorreparación, que en términos prácticos se podría ver como una mejora de su sostenibilidad. Finalmente, se sintetizan redes de PU que tienen un doble carácter estructural mediante enlaces iónicos de hidrógeno dinámicos y entrecruzamientos covalentes. La variación de la densidad de entrecruzamiento covalente introducido para cada una de estas redes produce un ajuste sistemático de las propiedades mecánicas y la sensibilidad del material al calor. Esta preparación demuestra una vía simple y eficaz para la fabricación de poliuretanos multifuncionales.
This Thesis is addressed to the development of side-chain functionalized polyurethanes (FPU)s, with enhanced properties, made from fatty acid-based functional diols and two different diisocyanates; isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI). The novel FPUs present tertiary amine and alkyl, allyl, propargyl moieties or the combination of these, as side-chain positions groups. The FPUs were further modified via two post-polymerization mechanisms based on covalent or non-covalent bonds. In the first case, photoinitiated thiol-ene/yne coupling reaction between allyl, propargyl-functionalized PUs (based on IPDI) and thioglycerol was carried out. Obtained hydroxyl-PUs exhibit different thermal and mechanical properties in comparison with precursor PUs. Moreover, the incorporation of hydroxyl groups leads to PUs with enhanced hydrophilicity. Alternatively, the FPU (based on IPDI) containing only tertiary amine pendant group was mixed with different carboxylic acids in an acid-base reaction. Supramolecular ionic PUs were characterized by spectroscopic tools to verify the presence of ionic hydrogen bond as ionic interaction. Correlation between structure and thermal and mechanical properties was demonstrated. Samples show rapid thermal reversibility and recyclability thanks to the reversible bonds. In addition, elastomeric supramolecular PUs networks were prepared from HDI and aminodiol. The resulting materials exhibit some promising adaptive material properties such as effective energy dissipation upon deformation through unzipping the ionic hydrogen bonding network, combined with good shape-regeneration property and recycling/reshaping capability arising from their recoverable nature. More importantly, the resulting biobased elastomers possess the inherent self-healing ability, which can be seen as an upgrade of their sustainability.A novel thermo-reversible network is constructed by the thiol-ene functionalized polyurethane via dynamic ionic hydrogen bonds and covalent cross-links. By varying the covalent cross-linking density, the mechanical properties and the stimuli-responsive behaviour can be systematically tuned. This synthesis demonstrates a simple and effective pathway to fabricate multifunctional polyurethanes with desired functions.
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Mati, Ioulia. "Molecular torsion balances for quantifying non-covalent interactions." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/7610.

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Non-covalent interactions underpin the whole of chemistry and biology, but their study is extremely difficult in complicated biological systems. This thesis presents the application of synthetic molecular balances for gaining fundamental insights into the physicochemical phenomena that govern molecular recognition processes. Chapter 1 reviews the use of small synthetic molecules that exist in two conformational states via slow rotation of a bond, in the quantification of non-covalent interactions. Chapter 2 presents a new molecular torsion balance, based on a slowly rotating tertiary formyl amide for the study of non-covalent interactions. The incorporation of a fluorine atom in one of the rings allows the quantification of solvent effects in a wide range of solvents. Intramolecular electrostatic interactions and intermolecular solvation effects (but not solvophobic effects) are shown to be important in determining the position of the conformational equilibria. Correlations with calculated molecular properties show that solvent effects are fully dissected, revealing the idealistic behavior of the system in the gas phase. Chapter 3 discusses through-space substituent effects on the properties of aromatic rings. Electronic communication between both electron-rich and electron-deficient substituents with the electron density of an adjacent aromatic ring is predicted by molecular electrostatic potential calculations. The effect is confirmed to occur experimentally and is quantified using synthetic molecular balances. Chapter 4 describes the work done towards the investigation of solvent bridging interactions in molecular torsion balances. No experimental evidence of bridging interactions was observed. This might be attributed to the entropic penalty associated with this binding mode, or the non-ideal geometry of the potential bridging sites. Chapter 5 outlines a steric blocking effect observed in certain balances with bulky substituents in chloroform and dichloromethane. Chapter 6 presents synthetic procedures and compound characterisation including a thorough analysis of NMR data obtained in this study.
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Benevelli, Francesca. "Solid-state NMR characterisation of non-covalent interactions." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620286.

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Abuajwa, Wissam. "Non-covalent interactions of C60 fullerene and its derivatives." Thesis, University of Nottingham, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.588068.

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In this thesis, the design and synthesis of novel C60 fullerene compounds with different functional groups is reported. Chapter 1 introduces the background of the project with a general introduction into the covalent and non-covalent types of bonding interactions, and the chemistry and reactions of C60 fullerenes. Chapter 2 focuses on co-crystallisation of pristine C60 with selected aromatic compounds. Single crystals have been obtained and characterised by X-ray diffraction. Chapter 3 is concerned with the synthesis and characterisation of novel fullerene compounds by using Prato cycloaddition reactions, such novel compounds are further characterised in the solid state by single crystal X-ray diffraction. Hirshfeld surfaces are used to investigate the non-covalent interaction of the obtained crystal structures. Chapter 4 describes the synthesis and characterisation of novel fullerene compounds by using Bingel cycloaddition reactions. Crystallisation experiments have been attempted and theoretical studies using the semi-empirical method, parameterized model number 3, have been employed to investigate the charge transfer between the ligand and the C60 molecule. The novel molecules in this work have been characterised by infrared and NMR spectroscopies, and mass spectrometry. Single crystal X-ray diffraction was used when appropriate.
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Adam, Catherine. "Molecular balances for measuring non-covalent interactions in solution." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/16466.

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Non-covalent interactions in solution are subject to modulation by surrounding solvent molecules. This thesis presents two experimental molecular balances that have been used to quantify solvent effects on non-covalent interactions, including electrostatic and dispersion interactions. The first chapter introduces literature where non-covalent interactions have been studied in a range of solvents, particularly those where the effects of aqueous or fluorous solvents have been investigated. These solvents are of particular interest as they both invoke solvophobic effects on organic molecules, but have differing chemical and physical properties. The second chapter describes the adaptation of the Wilcox molecular torsion balance to study interactions between organic and fluorinated carbon chains in a range of solvents. Solvent cohesion was found to be the principle force driving both the alkyl and fluorous chains together in aqueous solvents, where no contribution to the interaction energy arising from dispersion forces could be detected. In fluorous and polar organic solvents evidence was found for weak favourable dispersion interactions between the alkyl chains. In contrast dispersion forces between the chains were found to be disrupted by competitive van der Waals interactions with surrounding solvent molecules in apolar organic solvents. Association of the fluorous chains was found to be solely driven by solvent cohesion. The final chapter describes the design and synthesis of a novel synthetic molecular-balance framework and describes its application to simultaneously measure solvent and substituent effects on the position of conformational equilibria. Despite the simplicity of the model system, surprisingly complicated behaviour emerged from the interplay of conformational, intramolecular and solvent effects. Nonetheless, a large data set of experimental equilibrium constants was analysed using a simple solvent model, which was able to account for both the intuitive and more unusual patterns observed. A means of dissecting electrostatic and solvent effects to reveal pseudo gas-phase behaviour has resulted from the analysis of experimental data obtained in many solvents.
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Books on the topic "Covalent Interactions"

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Hobza, Pavel. Non-covalent interactions. Cambridge: Royal Society of Chemistry, 2009.

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Maharramov, Abel M., Kamran T. Mahmudov, Maximilian N. Kopylovich, and Armando J. L. Pombeiro, eds. Non-covalent Interactions in the Synthesis and Design of New Compounds. Hoboken, NJ: John Wiley & Sons, Inc, 2016. http://dx.doi.org/10.1002/9781119113874.

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Sinclair, Andrew Jamieson. Using non-covalent interaction to accelerate a [three plus two] dipolar cycloaddition reaction. Birmingham: University of Birmingham, 2000.

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Non-Covalent Interactions. Cambridge: Royal Society of Chemistry, 2009. http://dx.doi.org/10.1039/9781847559906.

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Non-Covalent Interactions in Proteins. World Scientific Publishing Co Pte Ltd, 2021.

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Karshikoff, Andrey. Non-Covalent Interactions in Proteins. WORLD SCIENTIFIC, 2021. http://dx.doi.org/10.1142/12035.

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Karshikoff, Andrey. Non-Covalent Interactions in Proteins. PUBLISHED BY IMPERIAL COLLEGE PRESS AND DISTRIBUTED BY WORLD SCIENTIFIC PUBLISHING CO., 2006. http://dx.doi.org/10.1142/p477.

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Barbier, Vincent, and Olivier R. P. David. Non-Covalent Interactions in Organocatalysis. Elsevier, 2018.

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Non-covalent Interactions in Proteins. Imperial College Press, 2006.

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Hobza, Pavel, Jonathan Hirst, Kenneth D. Jordan, Carmay Lim, and Klaus Muller-Dethlefs. Non-Covalent Interactions: Theory and Experiment. Royal Society of Chemistry, The, 2009.

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Book chapters on the topic "Covalent Interactions"

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Oscarsson, S., and J. Porath. "Covalent Chromatography." In Molecular Interactions in Bioseparations, 403–13. Boston, MA: Springer US, 1993. http://dx.doi.org/10.1007/978-1-4899-1872-7_26.

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Maharramov, Abel M., Kamran T. Mahmudov, Maximilian N. Kopylovich, M. Fátima C. Guedes da Silva, and Armando J. L. Pombeiro. "Activation of Covalent Bonds Through Non-covalent Interactions." In Non-covalent Interactions in the Synthesis and Design of New Compounds, 1–21. Hoboken, NJ: John Wiley & Sons, Inc, 2016. http://dx.doi.org/10.1002/9781119113874.ch1.

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Yon-Kahn, Jeannine, and Guy Hervé. "Regulation by Non-Covalent Interactions." In Molecular and Cellular Enzymology, 547–629. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-01228-0_14.

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Cheng, Yunfeng, Xiaochuan Yang, and Binghe Wang. "Covalent Interactions in Chemosensor Design." In Chemosensors, 25–40. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2011. http://dx.doi.org/10.1002/9781118019580.ch3.

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Hunter, Christopher. "Non-Covalent Interactions Between Aromatic Molecules." In From Simplicity to Complexity in Chemistry — and Beyond, 113–26. Berlin, Heidelberg: Springer Berlin Heidelberg, 1996. http://dx.doi.org/10.1007/978-3-642-49368-3_9.

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Aplin, Robin T., and Carol V. Robinson. "Electrospray Ionization Mass Spectrometry: The Observation of Covalent, Ionic and Non-Covalent Interactions." In Mass Spectrometry in the Biological Sciences, 69–84. Totowa, NJ: Humana Press, 1996. http://dx.doi.org/10.1007/978-1-4612-0229-5_4.

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D’Urso, Alessandro, Maria Elena Fragalà, and Roberto Purrello. "Non-Covalent Interactions of Porphyrinoids with Duplex DNA." In Topics in Heterocyclic Chemistry, 139–74. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/7081_2013_113.

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Kataev, Evgeny A. "Non-covalent Interactions in the Synthesis of Macrocycles." In Non-covalent Interactions in the Synthesis and Design of New Compounds, 63–82. Hoboken, NJ: John Wiley & Sons, Inc, 2016. http://dx.doi.org/10.1002/9781119113874.ch4.

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Sagan, Filip, and Mariusz P. Mitoraj. "Non-covalent Interactions in Selected Transition Metal Complexes." In Transition Metals in Coordination Environments, 65–89. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-11714-6_3.

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Chetverina, Helena V., and Alexander B. Chetverin. "Identifying RNA Recombination Events and Non-covalent RNA–RNA Interactions with the Molecular Colony Technique." In RNA-RNA Interactions, 1–25. New York, NY: Springer New York, 2014. http://dx.doi.org/10.1007/978-1-4939-1896-6_1.

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Conference papers on the topic "Covalent Interactions"

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Sanz, M., Jackson Tang, Elena Alonso, Isabel Peï¾–a, Donatella Loru, Ecaterina Burevschi, Shefali Saxena, and S. Murugachandran. "INTERMOLECULAR NON-COVALENT INTERACTIONS REVEALED BY BROADBAND ROTATIONAL SPECTROSCOPY." In 74th International Symposium on Molecular Spectroscopy. Urbana, Illinois: University of Illinois at Urbana-Champaign, 2019. http://dx.doi.org/10.15278/isms.2019.tb01.

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Caminati, Walther, Emilio Cocinero, Alberto Lesarri, Montserrat Vallejo-López, Lorenzo Spada, Gang Feng, Luca Evangelisti, and Qian Gou. "NON COVALENT INTERACTIONS AND INTERNAL DYNAMICS IN ADDUCTS OF FREONS." In 69th International Symposium on Molecular Spectroscopy. Urbana, Illinois: University of Illinois at Urbana-Champaign, 2014. http://dx.doi.org/10.15278/isms.2014.rj16.

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Foguel, Lidor, Patrick Vaccaro, and Zachary Vealey. "MICROSOLVATION AND THE EFFECTS OF NON-COVALENT INTERACTIONS ON INTRAMOLECULAR DYNAMICS." In 72nd International Symposium on Molecular Spectroscopy. Urbana, Illinois: University of Illinois at Urbana-Champaign, 2017. http://dx.doi.org/10.15278/isms.2017.wd02.

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Choe, Junseok, Keonwoo Kim, Minjae Ju, Sumin Lee, and Jaewoo Kang. "Improved Binding Affinity Prediction Using Non-Covalent Interactions and Graph Integration." In 2022 IEEE International Conference on Big Data and Smart Computing (BigComp). IEEE, 2022. http://dx.doi.org/10.1109/bigcomp54360.2022.00079.

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Melandri, Sonia, Laura Favero, Camilla Calabrese, Weixing Li, Imanol Gutierrez, Assimo Maris, and Luca Evangelisti. "TUNING OF NON-COVALENT INTERACTIONS IN MOLECULAR COMPLEXES OF FLUORINATED AROMATIC COMPOUNDS." In 73rd International Symposium on Molecular Spectroscopy. Urbana, Illinois: University of Illinois at Urbana-Champaign, 2018. http://dx.doi.org/10.15278/isms.2018.wk08.

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Oliveira, Vytor, and Elfi Kraka. "The intrinsic strength of non-covalent interactions described by coupled cluster theory." In VII Simpósio de Estrutura Eletrônica e Dinâmica Molecular. Editora Letra1, 2018. http://dx.doi.org/10.21826/9788563800374068.

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Melandri, Sonia, Laura Favero, Weixing Li, Camilla Calabrese, Imanol Usabiaga, Luca Evangelisti, and Assimo Maris. "NON-COVALENT INTERACTIONS IN COMPLEXES OF FLUORINATED AROMATIC RINGS INVESTIGATED BY ROTATIONAL SPECTROSCOPY." In 74th International Symposium on Molecular Spectroscopy. Urbana, Illinois: University of Illinois at Urbana-Champaign, 2019. http://dx.doi.org/10.15278/isms.2019.tb05.

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Belov, S. P., B. A. McElmurry, F. F. Willaert, R. R. Lucchese, and J. Bevan. "Co-axially configured supersonic jet spectrometer for submillimeter investigations of non-covalent interactions." In 2008 33rd International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz 2008). IEEE, 2008. http://dx.doi.org/10.1109/icimw.2008.4665616.

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Rackers, Joshua. "What can machine learning teach us about the limits of electron correlation?." In Proposed for presentation at the Non-Covalent Interactions in Large Molecules and Extended Materials in ,. US DOE, 2021. http://dx.doi.org/10.2172/1884653.

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Ma, Yingxian, Liqiang Huang, Zhi Zhu, Yurou Du, Jie Lai, and Jianchun Guo. "A Supramolecular Thickener Based on Non-Covalent Enhancement Mechanism." In SPE International Conference on Oilfield Chemistry. SPE, 2021. http://dx.doi.org/10.2118/204299-ms.

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Abstract Inspired by non-covalent enhancement mechanism, we introduced glycinamide-conjugated monomer (NAGA) with dual-amide in one side group to amplify the hydrogen bonding interactions. Via one-step free radical polymerization strategy, we prepared a type of supramolecular thickener based on binary polymer. With NMR, FT-IR and SEM results’ help, we determined that PNAGA-AM system had unique bis-amide structure of glycinamide-conjugated monomer. As a result, the synthesized polymer could generate a much denser structure based on the high-ordered multiple hydrogen bonding with lower molecular weight (Mn = 778,400 g/mol), increasing the strength and stability of the chains. PNAGA-AM system had good thickening and temperature-resistant properties. The thickener viscosity of PNAGA-AM(3.0wt%) had twice as much as that of corresponding PAM system. And the viscosity of the 1.5 wt% solution prepared by PNAGA-AM could maintain 74 mPa·s at 150 °C. Meanwhile, the supramolecular system showed excellent salt resistance and self-healing performance with the non-covalent/hydrogen bonding interactions and physical entanglements. The viscosity of the PNAGA-AM system did not drop but increase in high salinity (≤ 300,000 mg/L salinity), and the maximum viscosity could increase nearly 44 % compared with the initial situation. In addition, the self-healing efficiency was over 100 % at 120 °C. Overall, the fracturing fluid system based on PNAGA-AM system could maintain outstanding rheological properties under extreme conditions and showed brilliant recovery performance, to make up the disadvantages of currently used fracturing fluid. It is expected to mitigate potential fluid issues caused by low water quality, harsh downhole temperatures and high-speed shearing.
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Reports on the topic "Covalent Interactions"

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Nelson, Nathan, and Charles F. Yocum. Structure, Function and Utilization of Plant Photosynthetic Reaction Centers. United States Department of Agriculture, September 2012. http://dx.doi.org/10.32747/2012.7699846.bard.

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Light capturing and energy conversion by PSI is one of the most fundamental processes in nature. In the heart of these adaptations stand PSI, PSII and their light harvesting antenna complexes. The main goal of this grant proposal was to obtain by X-ray crystallography information on the structure of plant photosystem I (PSI) and photosystem II (PSII) supercomplexes. We achieved several milestones along this line but as yet, like several strong laboratories around the world, we have no crystal structure of plant PSII. We have redesigned the purification and crystallization procedures and recently solved the crystal structure of the PSI supercomplex at 3.3 Å resolution. Even though this advance in resolution appears to be relatively small, we obtained a significantly improved model of the supercomplex. The work was published in J. Biol. Chem. (Amunts et al., 2010). The improved electron density map yielded identification and tracing of the PsaK subunit. The location of an additional 10 ß-carotenes, as well as 5 chlorophylls and several loop regions that were previously uninterruptable have been modeled. This represents the most complete plant PSI structure obtained thus far, revealing the locations of and interactions among 17 protein subunits and 193 non-covalently bound photochemical cofactors. We have continued extensive experimental efforts to improve the structure of plant PSI and to obtain PSII preparation amenable to crystallization. Most of our efforts were devoted to obtain well-defined subcomplexes of plant PSII preparations that are amenable to crystallization. We studied the apparent paradox of the high sensitivity of oxygen evolution of isolated thylakoids while BBY particles exhibit remarkable resilience to the same treatment. The integrity of the photosystem II (PSII) extrinsic protein complement as well as calcium effects arise from the Ca2+ atom associated with the site of photosynthetic water oxidation were investigated. This work provides deeper insights into the interaction of PsbO with PSII. Sight-directed mutagenesis indicated the location of critical sites involved in the stability of the water oxidation reaction. When combined with previous results, the data lead to a more detailed model for PsbO binding in eukaryotic PSII.
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