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Thematische Bibliographien / Interaction cation-π

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Auswahl der wissenschaftlichen Literatur zum Thema „Interaction cation-π“

Autor: Grafiati

Veröffentlicht am 25. Mai 2024

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Zeitschriftenartikel zum Thema "Interaction cation-π"

1

Dougherty, Dennis A. „The Cation−π Interaction“. Accounts of Chemical Research 46, Nr. 4 (07.12.2012): 885–93. http://dx.doi.org/10.1021/ar300265y.

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Ma, Jennifer C., und Dennis A. Dougherty. „The Cation−π Interaction“. Chemical Reviews 97, Nr. 5 (August 1997): 1303–24. http://dx.doi.org/10.1021/cr9603744.

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3

Prampolini, Giacomo, Marco d'Ischia und Alessandro Ferretti. „The phenoxyl group-modulated interplay of cation–π and σ-type interactions in the alkali metal series“. Physical Chemistry Chemical Physics 22, Nr. 46 (2020): 27105–20. http://dx.doi.org/10.1039/d0cp03707a.

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An extensive exploration of the interaction PESs of phenol and catechol complexes with alkali metal cations reveals a striking effect of –OH substitution on the balance between cation-π and σ-type noncovalent interactions.

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Arnal-Herault, Carole, Mihail Barboiu, Eddy Petit, Mathieu Michau und Arie van der Lee. „Cation–π interaction: a case for macrocycle–cation π-interaction by its ureidoarene counteranion“. New Journal of Chemistry 29, Nr. 12 (2005): 1535. http://dx.doi.org/10.1039/b509240j.

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5

Ortolan, Alexandre O., Giovanni F. Caramori, Gernot Frenking und Alvaro Muñoz-Castro. „Role of the cation formal charge in cation–π interaction. A survey involving the [2.2.2]paracyclophane host from relativistic DFT calculations“. New Journal of Chemistry 39, Nr. 12 (2015): 9963–68. http://dx.doi.org/10.1039/c5nj02384j.

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6

Said, Musa A., Mohamed R. Aouad, David L. Hughes, Meshal A. Almehmadi und Mouslim Messali. „Synthesis and crystal structure of a new pyridinium bromide salt: 4-methyl-1-(3-phenoxypropyl)pyridinium bromide“. Acta Crystallographica Section E Crystallographic Communications 73, Nr. 12 (03.11.2017): 1831–34. http://dx.doi.org/10.1107/s2056989017015481.

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In the cation of the title molecular salt, C15H18NO+·Br−, the pyridinium and phenyl rings are inclined to one another by 11.80 (8)°. In the crystal, the Br−anion is linked to the cation by a C—H...Br hydrogen bond. The cations stack along theb-axis direction and are linked by further C—H...Br interactions, and offset π–π interactions [intercentroid distances = 3.5733 (19) and 3.8457 (19) Å], forming slabs parallel to theabplane. The effects of the C—H...X−interaction on the NMR signals of theortho-andmeta-pyridinium protons in a series of related ionic liquids,viz. 4-methyl-1-(4-phenoxybutyl)pyridin-1-ium salts, are reported and discussed.

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Kim, Hee-Joon. „Assembly of Sn(IV)-Porphyrin Cation Exhibiting Supramolecular Interactions of Anion···Anion and Anion···π Systems“. Molbank 2022, Nr. 4 (25.09.2022): M1454. http://dx.doi.org/10.3390/m1454.

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Trans-diaqua[meso-tetrakis(4-pyridyl)porphyrinato]Sn(IV) dinitrate complexes were assembled in a two-dimensional manner via hydrogen bonding between aqua ligands and pyridyl substituents. Interestingly, this supramolecular assembly was accompanied by unconventional noncovalent interactions, such as anion···anion and anion···π interactions, which were confirmed by X-ray crystallographic analysis. Two nitrate anions close to 2.070 Å were constrained in a confined space surrounded by four hydrogen-bonded Sn(IV)-porphyrin cations. The nitrate anion was also 3.433 Å away from the adjacent pyrrole ring, and the dihedral angle between the two mean planes was estimated to be 7.39°. The preference of the anion···π interaction was related to the electron-deficient π-system owing to the high-valent Sn(IV) center and cationic nature of the porphyrin complex. These two unconventional noncovalent interactions played an important role in the formation of a one-dimensional array with pairs of Sn(IV)-porphyrin cation and nitrate anion.

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Zhu, Yujie, Minmin Tang, Huibin Zhang, Faiz-Ur Rahman, Pablo Ballester, Julius Rebek, Christopher A. Hunter und Yang Yu. „Water and the Cation−π Interaction“. Journal of the American Chemical Society 143, Nr. 31 (30.07.2021): 12397–403. http://dx.doi.org/10.1021/jacs.1c06510.

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9

Miao, Junjian, Bo Song und Yi Gao. „Enhanced Aerogen-π Interaction by a Cation-π Force“. Chemistry - A European Journal 22, Nr. 8 (21.01.2016): 2586–89. http://dx.doi.org/10.1002/chem.201504210.

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10

Knop, Osvald, T. Stanley Cameron, Pradip K. Bakshi, Antony Linden und Stephen P. Roe. „Crystal chemistry of tetraradial species. Part 5. Interaction between cation lone pairs and phenyl groups in tetraphenylborates: crystal structures of Me3S+,Et3S+,Me3SO+,Ph2I+, and 1-azoniapropellane tetraphenylborates“. Canadian Journal of Chemistry 72, Nr. 8 (01.08.1994): 1870–81. http://dx.doi.org/10.1139/v94-238.

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Determination of the crystal structures of the tetraphenylborates of the trimethylsulfonium (Me3S+,P21/n), triethylsulfonium (Et3S+,Cmcm), trimethylsulfoxonium (Me3SO+,P21/m), diphenyliodonium (Ph2I+,Pnma), and 1-azoniapropellane (C10H18N+,P21/n) cations has shown that when regions of high local electron density (lone electron pairs) are present in the cation, the cation orients itself so as to minimize the repulsion between the lone pair(s) and the nearest anion phenyl groups, i.e. the cation orientation responds to the lone pair – aromatic π system interaction. This behaviour contrasts with the formation of H …π hydrogen bonds in tetraphenylborates of organic ammonium cations containing N-hydrogens and provides corroborative evidence for our previous finding: (1) given the opportunity, a cation N-hydrogen will form a hydrogen bond to a phenyl group(s) of the anion; (2) the orientation of the cation to form the N—H(N) …π bond is thus a manifestation of a positive hydrogen-bonding tendency rather than a passive response to overall packing requirements in the crystal. The geometries of the above cations are compared to those reported in the literature and those of Me3S+ and Me3SO+ have also been optimized by ab initio (RHF/6-31G*) methods.

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Dissertationen zum Thema "Interaction cation-π"

1

Mohiti, Maziar. „Asymmetric addition of chiral boronate complexes bearing π system to iminium intermediates exploiting cation-π interaction“. Thesis, University of Bristol, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.690759.

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Chen, Jing. „SOLUTION AND SOLID STATE INTERACTIONS BETWEEN IONIC π-SYSTEMS“. UKnowledge, 2006. http://uknowledge.uky.edu/gradschool_diss/289.

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Although attractive interactions between π systems (π-π interaction) have been known for many years, understanding of its origin is still incomplete. Quantitative measuring of π-stacking is challenging due to the weak nature of the π-π interaction. This dissertation aims at elucidating a quantitative conformational analysis by NMR ring current anisotropy of an organic compound capable of intramolecular π-stacking in solution and studying charge effects on the stacking of π-systems. This dissertation offers four contributions to the area. (1) A general approach to four-state, conformational analysis based on the magnetic anisotropy of molecules undergoing fast dynamic exchange is described. (2) Study unveiled the importance of charges in the conformation of a dication in the solution. (3) Novel aromatic salt pairs of triangulene derivatives with the delocalized cation-anion interaction were synthesized and studied. (4) Study unveiled ionic π-systems preferred face-to-face stacking due to strong cation-π and anion-cation attractions. A general protocol for the application of magnetic anisotropy to quantitative multi-state conformational analysis of molecules undergoing fast conformational exchange was suggested in the current study. The reliability of this method of conformational analysis was checked by the mass balance. VT-NMR was also conducted to study the enthalpic parameters. This technique can be further used to study canonical interactions such as ion pairing, hydrogen boning, and molecular recognition. In the current study, dependence of the probe conformations on the dispersive interactions at the aromatic edges between solvent and probes was tested by conformational distributions of the fluorinated derivatives (2b and 2c) of the probe molecule (1a). Solution and solid studies of these molecules put the previous conclusion drawn by the Cammers group in question. Current studies show that the dispersive interaction at the aromatic edge could not be the predominant force on the conformational changes in the probe molecule 1a during the fluoroalkanol perturbation. This study indicated that charges might be important in the formation of the folding conformations in the solution and solid state of 1a, 2b, and 2c. A contribution of this thesis was to prepare and study a conformational model that lacked charges. The previous molecules were charged. The solid-state structures of pyridinium-derived aromatic rings from the CSD (Cambridge Structural Database) were studied to investigate the π-π interaction between cationic π-systems in solid state. Novel aromatic salt pairs of triangulene derivatives with the delocalized cation-anion interaction were synthesized to study the π-π interaction between two aromatic rings that carried opposite charges. This study showed that the interaction between ionic π-systems can be enhanced by cation-π and anion-cation attractions. The stackings of these π-systems introduce more overlap, closer packing and stronger atomic contact than that of the solid states of comparable neutral species. Cation-π and anion-cation attractions are synergistic in aromatic salts.

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He, Tao. „I. Exploration of Amphitropic Protein Interactions at the Membrane Interface; II. DNF2—A Plant Protein with Homology to Bacterial PI-PLC Enzymes“. Thesis, Boston College, 2015. http://hdl.handle.net/2345/bc-ir:104815.

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Thesis advisor: Mary F. Roberts
Amphitropic proteins, such as the virulence factor phosphatidylinositol-specific phospholipase C (PI-PLC) from Bacillus thuringiensis, often depend on lipid-specific recognition of target membranes. However, the recognition mechanisms for zwitterionic lipids such as phosphatidylcholine (PC), which is enriched in the outer leaflet of eukaryotic cell membranes, are not well understood. Molecular dynamics (MD) simulation and mutagenesis results strongly indicate that PI-PLC interacts with PC head groups via cation-π interactions with aromatic tyrosine residues, and suggest that cation-π interactions at the interface may be a mechanism for specific lipid recognition by amphitropic and membrane proteins. Aromatic amino acids can not only form cation-π interactions at the interface but also insert into membranes and have hydrophobic interactions with lipid tails. Heretofore there has been no facile way to differentiate these two types of interactions. We show that specific incorporation of fluorinated amino acids into proteins can experimentally distinguish cation-π interactions from membrane insertion of the aromatic side-chains. Fluorinated aromatic amino acids destabilize the cation-π interactions by altering electrostatics of the aromatic ring while their enhanced hydrophobicity enhances membrane insertion. Incorporation of pentafluorophenylalanine or difluorotyrosine into a Staphylococcus aureus phosphatidylinositol-specific phospholipase C (PI-PLC) variant engineered to contain a specific PC-binding site demonstrates the effectiveness of this methodology. Applying this methodology to the plethora of tyrosine residues in Bacillus thuringiensis PI-PLC identifies those involved in cation-π interactions with PC. Cation-π interactions provide a likely molecular mechanism for BtPI-PLC PC specificity but do not account for its preference for bilayers containing a small fraction of anionic lipids. MD simulations and fluorescence correlation spectroscopy (FCS) vesicle binding measurements of positively charged amino acids as well as surface tyrosine residues are used to formulate a complete model of BtPI-PLC specific binding to mixed anionic phospholipid/PC membrane. DNF2, a new plant protein with homology to bacterial PI-PLC, is confirmed to be the first plant small PI-PLC enzyme that can cleave both PI and glycosylphosphatidylinositol (GPI) anchored proteins. GPI-anchored protein cleavage also confirms that DNF2 plays an important role in symbiosome, the intracellular compartment formed by the plant that contains nitrogen fixing bacteria
Thesis (PhD) — Boston College, 2015
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry

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Ortega, Varga Laura. „Innovative inhibition strategy against functional structural transitions of essential pathogenic factors : Computational applications to Malarial and Neurotransmitter targets“. Electronic Thesis or Diss., Sorbonne université, 2019. http://www.theses.fr/2019SORUS455.

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Ce projet de thèse décrit la conception d'inhibiteurs de deux enzymes de l'agent du paludisme et de modulateurs de la sous-unité α5 des récepteurs nicotiniques de l'acétylcholine (nAChR) impliqués dans les dépendances. La subtilase de Plasmodium vivax (SUB1), nécessaire pour la sortie des parasites des cellules a été ciblée avec des inhibiteurs covalents réversibles. Nous avons effectué un docking covalent de peptidomimétiques candidats et étudié leur cyclisation. Plusieurs mimétiques ont montré une activité sub-micromolaire et leur structure a pu être résolue par co-cristallisation. Nous avons ciblé la lactate déshydrogénase, essentielle au métabolisme de Plasmodium falciparum avec des inhibiteurs conçus par analogie du tandem cofacteurs-substrat. Nous avons construit une bibliothèque combinatoire que nous avons criblé in silico, en évitant de cibler les isoenzymes humaines. Nous avons sélectionné une cinquantaine de molécules, en cours de synthèse pour tests ex vivo. Enfin, pour lutter contre les dépendances, une chimère α5-α4 de l'AChBP a été utilisée dans une approche multidisciplinaire. La structure en complexe avec les premiers ligands connus d'α5 a été résolue et nous l'avons utilisée avec deux modèles comparatifs pour un criblage in silico. Nous avons introduit l'interaction cation-π dans le logiciel FlexX, autorisé des chaînes latérales flexibles dans le site de liaison et développé un pipeline interactif pour l'analyse des résultats de criblage virtuel. Les molécules obtenues ont été confirmées par des expériences STD-RMN. Des modèles de réseaux neuronaux profonds ont également été construits pour prédire la bioactivité sur cible et hors cible
This PhD project describes the design of inhibitors of two essential malaria enzymes and of novel modulators of specific nicotinic acetylcholine receptors (nAChRs). Plasmodium vivax subtilase SUB1 is required for parasite egress. We focused our efforts on the design of reversible covalent inhibitors of PvSUB1. We performed covalent docking of potential peptide and peptidomimetic candidates and studied peptide cyclization. Several peptides have shown activity in the submicromolar range and could be resolved after co-crystalization. Plasmodium falciparum lactate dehydrogenase is critical for parasite metabolism. We targeted it by design on the basis of inhibitory cofactor analogs. We have built a combinatorial library aiming to bridge the cofactor and the substrate binding site, while avoiding affecting the human isoenzymes. We screened it in silico and selected about fifty molecules that are under synthesis for ex vivo testing. We also targeted α5 subunit containing nAChRs to address addiction. A multidisciplinary approach has been established. It uses an AChBP engineered chimera, which structure was solved in complex with the first known 5 ligands. This structure, and two comparative modeling models were used to perform in silico screening. A cation-π interaction definition was introduced in the FlexX software and side chain flexibility was allowed in the binding site. An interactive pipeline was developed for the analysis of the virtual screening results and hit molecules have been confirmed by STD-NMR experiments. Deep neural networks models were also built to assess on- and off-target bioactivity prediction in a panel of nAChRs and putative off-targets

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Berry, Bruce W. „Using de novo design proteins to explore tyrosine radicals and cation-π interactions“. Doctoral thesis, Stockholms universitet, Institutionen för biokemi och biofysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-102008.

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Redox cofactors and amino-acid free radicals play important roles in biology. Although many of the same cofactors and amino acids that form these radicals are found across a broad range of biological systems, identical cofactors can have different reduction potentials. The local environment plays a role in defining these redox potentials. An understanding of this local-environment effect can shed more light on how redox chemistry works in nature. Our laboratory has developed a library of model proteins that are well suited to study amino-acid radicals. a3X is a de novo designed protein that is composed of 67 residues. It forms a three-helix bundle connected by two glycine loops. The radical site is located at position 32 on the central a-helix. The a3X protein is designed to be well-folded and thermodynamically stable across a broad pH range. Paper 1 describes the structural and electrochemical characterization of a3Y, a tyrosine variant of a3X. We were able to obtain a unique Faradaic response from Y32 at both low and high pH, using differential pulse voltammetry. In addition, we successfully redesigned α3Y by introducing a histidine in close proximity to Y32, creating a tyrosine/histidine pair. Our goal in creating this pair was to study proton-coupled electron transfer (PCET) in a well-structured and solvent-sequestered protein environment. In paper 2 we illustrated the redox reversibility of Y32 and produced the first ever Pourbaix diagram for a tyrosine radical in a protein. The formal potential of the Y32-O/Y32-OH redox couple was determined to be 918 ± 2 mV vs. the normal hydrogen electrode (NHE) at pH 8.40. While at pH 5.52, the formal potential of the Y32-O/Y32-OH redox couple was recorded at 1.07 V. Papers 3 and 4 utilize a3W to study cation-π interactions. In paper 3, we showed how solvation can affect the strength of these interactions by -0.9 kcal/mol. In Paper 4, we were able to monitor the disruption of the cation-π interaction with the use of high-pressure fluorescence and were able to calculate the interaction energy for a solvent exposed cation-π. The aim of the work described in this thesis was to use model proteins to study tyrosine radicals to gain a broader perspective and better understanding of the versatility of biological electron transfer and to measure cation-π interactions and how they behave in different environments.

At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Manuscript.

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Arnal-Hérault, Carole. „Matériaux biomimétiques adaptatifs programmés par auto-assemblage de nucléobases ou par interactions cation-π“. Montpellier 2, 2006. http://www.theses.fr/2006MON20100.

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Alshamrani, Nouf. „Cation-π Interactions of Selected Alkali Metal Ions with Two Benzene Rings Connected through Linear Chains“. DigitalCommons@Robert W. Woodruff Library, Atlanta University Center, 2018. http://digitalcommons.auctr.edu/cauetds/147.

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Quantum chemical calculations at M06-2X/6-311+G(2d,2p) level were employed to examine the structures, dissociation energies and vibrational spectra of complexes formed by Li+, Na+ and K+ with diphenylmethane, 1,2-diphenylethane, 1,3-diphenylpropane, [2.2]paracyclophane and [3.3]paracyclophane molecules. The effect of heteroatom substitution in the connecting chains of 1,3-diphenylpropane and [3.3]paracyclophane molecules on the binding affinity of cations with ligands was also included in this study. The complexes of [3.3] paracyclophane based molecules seem to have weak cation-pi interactions with metal ions Na+ and K+ when they were placed between two rings. The binding affinity of the metal ion varies from the ligands possessing single fusion to double fusion of alkyl chain (or hetero substituted alkyl chain) with two benzene rings. Vibrational frequencies related to metal-ligand stretching, C-H, N-H and P-H stretching are useful to characterize the complexes with different metal ions and their positional preference.

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Mihai, Simona. „Systèmes biomimétiques multifonctionnels via des interactions cation-π, sucres-protéines et autoassemblages de quartets de guanosine“. Montpellier 2, 2009. http://www.theses.fr/2009MON20217.

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Le fonctionnement du monde vivant repose sur des processus de reconnaissance moléculaire entre les différents partenaires. Cette reconnaissance a lieu grâce à diverses interactions faibles non covalentes. Dans le cadre de ce travail de thèse nous nous sommes intéressés aux processus de reconnaissance moléculaire impliquant les chaînes latérales d'aminoacides aromatiques rencontrées dans l'adhésion cellulaire, le transport de divers cations et la reconnaissance de neurotransmetteurs au niveau des synapses du système nerveux central. Nous avons ainsi mis en évidence la compléxation de carbohydrates par des noyaux aromatiques au travers d'interactions CH-pi ainsi que la complexation de divers sels organiques et inorganiques au travers d'interactions cation-pi par ces mêmes récepteurs. Nous avons ainsi réalisé le transport compétitif de neurotransmetteurs au travers d'une membrane hybride alumino-siliciée fonctionnalisée par nos récepteurs synthétiques. D'autre part, nous avons accordé une importance particulière à la superstructure dynamique formée de quartets de guanosine et cherché notamment à observer le transfert de chiralité de cette structure à la matrice inorganique durant un processus sol gel. Nous avons également stabilisé les G-quadruplexes dans un milieu confiné silicié et avons développé une méthode d'encapsulation de principes actifs basée sur la reconnaissance spécifique des G4
The functioning of the living world rests on processes of molecular recognition between the various partners. This recognition takes place thanks to diverse weak interactions not covalentes. Within the framework of this work of thesis we were interested in the processes of molecular recognition involving the side chains of aromatic aminoacides met in the cellular membership, the transport of diverse cations and the recognition of neurotransmitters at the level of the synapses of the central nervous system. We so put in evidence the compléxation of carbohydrates by aromatic nuclei through interactions CH-pi as well as the compléxation of diverse organic and inorganic salts through interactions cation-pi by these same receivers. We so realized the competitive transport of neurotransmitters through a hybrid membrane alumino-siliciée fonctionnalisée by our synthetic receivers. On the other hand, we granted a particular importance for the dynamic superstructure formed by quartets of guanosine and tried in particular to observe the transfer of chirality of this structure in the inorganic matrix during a sol-gel process. We also stabilized G-quadruplexes in a stuffy silicié environment and developed a method of encapsulation of active principles based on the specific recognition of G4

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Pratuangdejkul, Jaturong. „Modélisation moléculaire de la sérotonine et de son transporteur“. Paris 5, 2005. http://www.theses.fr/2005PA05P634.

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L'objet de cette thèse a été dans un premier temps d'établir les relations quantitatives entre la structure et l'activité en trois dimensions (3D-QSAR) de 121 composés chimiques afin de déterminer les propriétés physicochimiques requises pour que ces molécules soient transportées par SERT. A partir de cette étude nous avons pu élaborer un pharmacophore du transport par SERT. Nous avons basé cette première étude sur une analyse conformationnelle exhaustive de la sérotonine par chimie quantique. Nous avons pu montrer d'une part que les forces électrostatiques qui influencent la conformation de la sérotonine sont majoritairement des interactions cation-p, avec une participation non négligeable d'un transfert de charge. Et d'autre part, que ces mêmes forces conditionnent les deux pKa de la sérotonine correspondant à l'ionisation des groupements ammonium et hydroxyle en 5, que nous avons pu prédire par calculs quantiques, en bon accord avec les valeurs expérimentales
The object of this thesis was initially to establish the three dimensions quantitative structure-activity relationships (3D-QSAR) of 121 chemical compounds in order to determine the necessary physicochemical properties of these molecules transported through SERT. From this study we extracted a pharmacophore for the 3D definition of compound transported by SERT. We have based this study on an exhaustive conformational analysis of serotonin by quantum chemistry. We could show that the electrostatic forces which influence the conformation of serotonin are mainly due to cation-p interactions with a predominant participation of a charge transfer. We also showed that these non-bonded forces influence the two pKa of serotonin that correspond to the ionization of the ammonium and 5-hydroxyl groups. We could predict both pKa's in agreement with the experimental values by using ab initio calculations

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Kotze, Izak Aldert. „Self-association of [PtII(1,10-Phenanthroline)(N-pyrrolidyl-N-(2,2-dimethyl-propanoyl)thiourea)]+ and non-covalent outer-sphere complex formation with fluoranthene through cation-π interactions : a high resolution 1H and DOSY NMR study“. Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/1796.

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Bücher zum Thema "Interaction cation-π"

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Yamada, Shinji. The Cation–π Interaction. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-7335-2.

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Buchteile zum Thema "Interaction cation-π"

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Yamada, Shinji. „Materials Science“. In The Cation–π Interaction, 145–94. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-7335-2_5.

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Yamada, Shinji. „Introduction“. In The Cation–π Interaction, 1–5. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-7335-2_1.

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Yamada, Shinji. „Biological Systems“. In The Cation–π Interaction, 43–93. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-7335-2_3.

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Yamada, Shinji. „Fundamentals of Cation–π Interactions“. In The Cation–π Interaction, 7–41. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-7335-2_2.

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Yamada, Shinji. „Organic Synthesis“. In The Cation–π Interaction, 95–143. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-7335-2_4.

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Velazquez, Hector Adam, und Donald Hamelberg. „Ionic, Hydrogen Bond, and π-Cation Interactions“. In Chemosensors, 19–24. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2011. http://dx.doi.org/10.1002/9781118019580.ch2.

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Jorgensen, William L., Daniel L. Severance und Erin M. Duffy. „Modeling Interactions with Benzene: Aryl-Aryl, Cation-π, and Chaotrope-π“. In Computational Approaches in Supramolecular Chemistry, 161–73. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-1058-7_11.

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Sha, Wei, Rieko Arimoto und Garland R. Marshall. „Receptor-Bound Conformation of α-Peptide of Transducin (Gt) is not Stabilized by a “π-Cation” Interaction but by Constrained Lactam Bridges Between Residues 341 and 350“. In Peptides: The Wave of the Future, 909–10. Dordrecht: Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-010-0464-0_424.

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9

Mahadevi, A. Subha, und G. Narahari Sastry. „Computational Approaches Towards Modeling Finite Molecular Assemblies: Role of Cation-π, π–π and Hydrogen Bonding Interactions“. In Practical Aspects of Computational Chemistry I, 517–55. Dordrecht: Springer Netherlands, 2011. http://dx.doi.org/10.1007/978-94-007-0919-5_18.

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Yamada, Shinji. „CHAPTER 6. Onium Ion-assisted Organic Reactions Through Cation–π Interactions“. In Catalysis Series, 137–52. Cambridge: Royal Society of Chemistry, 2019. http://dx.doi.org/10.1039/9781788016490-00137.

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Konferenzberichte zum Thema "Interaction cation-π"

1

Malenov, Dušan P., Katarina A. Ćeranić, Dubravka Z. Vojislavljević-Vasilev und Snežana D. Zarić. „Modeling ion-π interactions of transition metal complexes“. In 2nd International Conference on Chemo and Bioinformatics. Institute for Information Technologies, University of Kragujevac, 2023. http://dx.doi.org/10.46793/iccbi23.621m.

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Interactions of π-systems with ions are very important for many chemical and biological systems. In this work we show how transition metal coordination strengthens cation-π interactions, and how it makes anion-π interactions of some systems possible. The calculations showed that cation-π interactions between ferrocene and alkali metal ions are stronger than cation-π interactions of benzene. The strongest cation-π interaction is between ferrocene and Li+, with interaction energy of -44.0 kcal/mol, while benzene-Li+ interaction has the energy of -36.1 kcal/mol. Cation-π interactions can also involve transition metal complexes as cations, with [Co(NH3)6] 3+/benzene interaction being very strong (-31.4 kcal/mol), while [Zn(H2O)6]2+/benzene interaction somewhat weaker (-14.0 kcal/mol). Anion-π interactions of unsubstituted aromatic rings without heteroatoms are possible if they are ligands in organometallic half-sandwich complexes with electron-withdrawing ligands. The anion-π interactions of such transition metal complexes with halides can reach the energy of -25.0 kcal/mol, and they are stronger than anion-π interactions of organic aromatic molecules.

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Carrazana-Garcia, Jorge, Enrique Cabaleiro Lago und Jesus Rodriguez Otero. „Theoretical study on cation–π interaction in graphene fragments“. In The 23rd International Electronic Conference on Synthetic Organic Chemistry. Basel, Switzerland: MDPI, 2019. http://dx.doi.org/10.3390/ecsoc-23-06497.

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3

Gorbachev, Vladimir, Peter Chen, Larisa Miloglyadova und Alexandra Tsybizova. „CAN LONDON DISPERSION OVERRIDE CATION- π INTERACTIONS?“ In 2022 International Symposium on Molecular Spectroscopy. Urbana, Illinois: University of Illinois at Urbana-Champaign, 2022. http://dx.doi.org/10.15278/isms.2022.wi03.

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4

WONG, Y. P., K. M. NG und C. W. TSANG. „CATION-π INTERACTIONS IN AG(I)-SUBSTITUED ALKYLBENZENES COMPLEXES: A THEORETICAL STUDY“. In Proceedings of the International Conference on Scientific and Engineering Computation (IC-SEC) 2002. PUBLISHED BY IMPERIAL COLLEGE PRESS AND DISTRIBUTED BY WORLD SCIENTIFIC PUBLISHING CO., 2002. http://dx.doi.org/10.1142/9781860949524_0003.

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5

LEE, H. M., und C. W. TSANG. „CATION-π INTERACTIONS IN AG(I)-SUBSTITUTED NAPHTHALENE COMPLEXES: AN AB INITIO MOLECULAR ORBITAL STUDY“. In Proceedings of the International Conference on Scientific and Engineering Computation (IC-SEC) 2002. PUBLISHED BY IMPERIAL COLLEGE PRESS AND DISTRIBUTED BY WORLD SCIENTIFIC PUBLISHING CO., 2002. http://dx.doi.org/10.1142/9781860949524_0013.

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6

Milenković, Dejan A., Marko N. Živanović, Milan S. Dekić, Marijana Stanojević Pirković und Jelena R. Đorović Jovanović. „CYTOTOXIC ACTIVITY AND MOLECULAR DOCKING STUDY OF 4- SUBSTITUTED FLAVYLIUM SALT“. In 1st INTERNATIONAL Conference on Chemo and BioInformatics. Institute for Information Technologies, University of Kragujevac,, 2021. http://dx.doi.org/10.46793/iccbi21.466m.

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In the present manuscript, the cytotoxic activity of flavylium cation substituted at 4- position with phenyl (FC-4Ph) was tested to two cells lines (human colorectal carcinoma, HCT-116, and human fibroblast lung, MRC-5). In vitro cytotoxicity experiments were performed to elucidate the possible anticancer activity of tested substance. Investigated compound did not show cytotoxic effect on HCT-116 after 24 h, while after 72 h exerted significant effect. A significant selectivity towards colorectal carcinoma cells was observed. On the other hand, this compound did not show any effect on MRC-5 cell line. The molecular interactions between receptor tyrosine kinase (RTK) and title compound was examined. The crystal structure of investigated receptor RTK was downloaded from Protein Data Bank. The native bound ligand ((E)-[4-(3,5-difluorophenyl)-3H-pyrrolo[2,3-b]pyridin-3-ylidene](3- methoxyphenyl)methanol was extracted from receptor and binding pocket analysis was performed. Re-docking was carried out with the FC-4Ph in order to generate the same docking pose as found in co-crystallized form of receptor. The obtained results of revealed that investigated compound binds at the same binding pockets to RTK, as well as native bound ligand, by weak non-covalent interactions. The most prominent interactions are hydrogen bonds, π-alkyl, and π-π interactions. The preliminary results suggest that investigated compound showed good binding affinity against RTK, as evident from the free binding energy (ΔGbind in kJ/mol).

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Brathwaite, Antonio, Michael Duncan, TIMOTHY WARD und Richard Walters. „CATION-π AND CH-π INTERACTIONS IN THE COORDINATION AND SOLVATION OF Cu+ (ACETYLENE)n (n=1-6) COMPLEXES INVESTIGATED VIA INFRARED PHOTODISSOCIATION SPECTROSCOPY“. In 70th International Symposium on Molecular Spectroscopy. Urbana, Illinois: University of Illinois at Urbana-Champaign, 2015. http://dx.doi.org/10.15278/isms.2015.ra09.

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8

Meybodi, M. Kalantari, K. S. Sorbie, O. Vazquez, K. Jarrahian und E. J. Mackay. „Coupled Adsorption/Precipitation Modelling of Phosphonate Scale Inhibitors in a Batch Reactive System“. In SPE International Conference and Exhibition on Formation Damage Control. SPE, 2024. http://dx.doi.org/10.2118/217904-ms.

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Abstract Scale inhibitor squeeze treatments are one of the most common ways to prevent scale deposition. The mineral scale will be inhibited if the concentration of the scale inhibitor (SI) in the produced water is above a certain threshold, known as the Minimum Inhibitor Concentration (MIC), which is controlled by scale inhibitor retention. Therefore, accurate modelling of the SI retention through adsorption (Γ) and precipitation (Π) is critical to the successful design and implementation of squeeze treatments. In this study, an equilibrium model has been developed to simulate the coupled adsorption-precipitation (Γ/Π) of phosphonate scale inhibitors in reactive formations, such as carbonates, in the presence of calcium and magnesium cations. In this approach, the scale inhibitor (SI) was considered as a poly weak acid that may be protonated (HnA), resulting in the complexation with Ca/Mg ions, leading to the precipitation of SI_Ca/Mg complexes. All these reactions occur in an integrated system where carbonate system reactions and adsorption of the soluble species are occurring in parallel. In the adsorption process, all the SI derivatives remaining in the solution, including free and complex species, are considered to participate in the adsorption process, described by an an adsorption isotherm model (e.g., Freundlich). For the precipitation part, the model considers the following reactions: (i) the carbonate system, (ii) SI speciation, considered as weak polyacid, HnA, (iii) the SI-metal (Ca and Mg) binding complexes, and (iv) subsequent precipitation of the SI-Ca/Mg complex. The system charge balance and the mass balances for calcium, magnesium, carbon, and SI are considered, to numerically equilibrate the system (excluding the adsorbed species), by solving a determined set of non-linear equations numerically. Following the algebraic reduction of the equations, the system is reduced to three non-linear equations that may be solved by the Newton-Raphson method. The precipitation of the SI-Ca/Mg is modelled in the equilibrium model based on the solubility of SI in the solution, determined from the lab experiments. The reliability of the proposed model was established by comparison with experimental results from a previous study (Kalantari Meybodi et al., 2023) on the interactions of DETPMP in a Calcite/brine (containing free Ca/Mg) system, where the final concentration of SI, Ca2+, Mg2+, CO2 and pH were compared. The modelling showed good general agreement with the experimental results, and a further sensitivity analysis was performed to examine the behaviour of some uncertain parameters, such as the stability constant of complexes.

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