Polarizability anisotropy, magnetic anisotropy, and quadrupole moment of cyclohexane

Craven, Ian E.; Hesling, Mark R.; Laver, Derek R.; Lukins, P. B.; Ritchie, G. L. D.; Vrbancich, Julian

doi:10.1021/j100339a026

Cited by 45 publications

(23 citation statements)

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“…Azulene (16) presents quite a potent cation-IT binding site, and, as expected, the cation is centered on the five-membered ring. Finally, cyclohexane (17) is included as a structure of comparable size but with no significant electrostatic binding [near zero quadrupole moment (20)]. It is a very weak binder.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Cation-pi interactions in aromatics of biological and medicinal interest: electrostatic potential surfaces as a useful qualitative guide.

Mecozzi

West²,

Dougherty³

1996

Proc. Natl. Acad. Sci. U.S.A.

579

554

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The cation-t interaction is an important, general force for molecular recognition in biological receptors. Through the sidechains of aromatic amino acids, novel binding sites for cationic ligands such as acetylcholine can be constructed. We report here a number of calculations on prototypical cation-7r systems, emphasizing structures of relevance to biological receptors and prototypical heterocycles of the type often of importance in medicinal chemistry. Trends in the data can be rationalized using a relatively simple model that emphasizes the electrostatic component of the cation-ir interaction. In particular, plots of the electrostatic potential surfaces of the relevant aromatics provide useful guidelines for predicting cation-7r interactions in new systems.of relevance to biological receptors and prototype heterocycles of the type often of importance in medicinal chemistry. We find that all the trends in this series are qualitatively reproduced by considering only the electrostatic potential energy surface of the aromatic in the absence of a cation, consistent with the electrostatic model. In addition, the current model successfully rationalizes observations concerning the relative frequency of different aromatic amino acids at biological cation-Ir sites. We also show that the major trends of the ab initio surfaces are reproduced using the much less costly AM1 method, greatly expanding the range of applicability of the method.In recent years, studies of model systems and the analysis of biological macromolecular structures have established the importance of the cation-rr interaction as a force for molecular recognition in aqueous media (1). Appropriately designed cyclophane receptors serve as powerful, general hosts for quaternary ammonium, sulfonium, and guanidinium cations, in large part because of the cation-IT interaction (2-4). In the gas phase, the binding of simple cations to benzene and related structures has been shown to be quite substantial, comparable even to cation-water interactions (5). In addition, a large amount of evidence has now been developed that establishes cation-IT interactions as important in a number of biological binding sites for cations (1,6,7). Cation-IT interactions have been considered in such diverse systems as acetylcholine receptors (nicotinic, muscarinic, and ACh esterase), K+ channels, the cyclase enzymes of steroid biosynthesis, and enzymes that catalyze methylation reactions involving S-adenosylmethionine (1). Cation-Ir interactions have also been invoked to rationalize specific drug-receptor interactions (8)(9)(10)(11)

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Section: Resultsmentioning

confidence: 99%

“…It is a very weak binder. Note that if polarizability were the dominant factor in establishing the magnitude of a cation-Ir interaction, one might have expected cyclohexane to outperform benzene, since it is known to be more polarizable than benzene (20,21). Of course, this is not the case, emphasizing the importance of the electrostatic term.…”

Section: Resultsmentioning

confidence: 99%

Cation-pi interactions in aromatics of biological and medicinal interest: electrostatic potential surfaces as a useful qualitative guide.

Mecozzi

West²,

Dougherty³

1996

Proc. Natl. Acad. Sci. U.S.A.

579

554

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“…[33] Experimentally,there is growing evidence that dispersion plays an essential role in what is considered to be aw eak hydrogen bond:A na romatic alcohol interacts 35 %m ore strongly with acyclohexanethan with abenzene molecule; [34] cyclohexane is actually more polarizable than benzene. [35] The interaction of alkanes with benzene correlates with their polarizability,b ut not with the number of CH-p contacts. [36] Understanding the length scale for the transition from the continuum (where LD forces are dominant) to the atoms and the domain of covalent and ionic bonds is key for the development and understanding of materials,a nd for the exploration of the transition of the molecular to the material domain.…”

Section: Methodsmentioning

confidence: 99%

London Dispersion in Molecular Chemistry—Reconsidering Steric Effects

2015

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London dispersion, which constitutes the attractive part of the famous van der Waals potential, has long been underappreciated in molecular chemistry as an important element of structural stability, and thus affects chemical reactivity and catalysis. This negligence is due to the common notion that dispersion is weak, which is only true for one pair of interacting atoms. For increasingly larger structures, the overall dispersion contribution grows rapidly and can amount to tens of kcal mol(-1) . This Review collects and emphasizes the importance of inter- and intramolecular dispersion for molecules consisting mostly of first row atoms. The synergy of experiment and theory has now reached a stage where dispersion effects can be examined in fine detail. This forces us to reconsider our perception of steric hindrance and stereoelectronic effects. The quantitation of dispersion energy donors will improve our ability to design sophisticated molecular structures and much better catalysts.

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“…[33] Es gibt eine wachsende Zahl experimenteller Hinweise darauf,d ass Dispersion eine entscheidende Rolle selbst bei schwachen Wasserstoffbrücken spielt:E in aromatischer Alkohol wechselwirkt 35 %s tärker mit Cyclohexan als mit einem Benzolmolekül; [34] überraschenderweise ist Cyclohexan polarisierbarer als Benzol. [35] Die Wechselwirkung von Benzol mit Alkanen korreliert mit deren Polarisierbarkeit und eben nicht mit der Anzahl der CH-p-Kontakte. [36] Die Längenskala des Übergangs vom Kontinuum (in dem LD dominiert) zum Reich der Atome mit deren kovalenten und ionischen Bindungen ist der Schlüssel zu Entwicklung und Verständnis neuartiger Materialien sowie auch für die Erforschung des Übergangs von der molekularen zur makroskopischen Ebene (Materialchemie).…”

Section: à6unclassified

London’sche Dispersionswechselwirkungen in der Molekülchemie – eine Neubetrachtung sterischer Effekte

2015

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Die London’sche Dispersion, die den attraktiven Teil des Van‐der‐Waals‐Potentials beschreibt, wurde lange als Element struktureller Stabilität in der molekularen Chemie unterschätzt. Als solches beeinflusst sie auch entscheidend die chemische Reaktivität und Katalyse. Ihre Vernachlässigung ist auf die Annahme zurückzuführen, dass die Dispersionswechselwirkung schwach sei, was nur für eine einzelne paarweise Wechselwirkung zweier Atome stimmt. Für Strukturen zunehmender Größe kann die gesamte Dispersionsstabilisierung mehrere zehn kcal mol−1 betragen. Dieser Aufsatz soll die Wichtigkeit inter‐ und intramolekularer Dispersion anhand von Beispielen für die erste Vollperiode verdeutlichen. Die Synergie aus Experiment und Theorie hat ein Niveau erreicht, auf dem Dispersionseffekte sehr genau verstanden werden können. Als Konsequenz daraus werden wir wohl unser Verständnis bezüglich sterischer Hinderung und stereoelektronischer Effekte überdenken müssen. Die Quantifizierung von Dispersionsenergiedonoren wird unsere Fähigkeiten verbessern, komplexe molekulare Strukturen und Katalysatoren zu entwickeln.

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Polarizability anisotropy, magnetic anisotropy, and quadrupole moment of cyclohexane

Cited by 45 publications

References 0 publications

Cation-pi interactions in aromatics of biological and medicinal interest: electrostatic potential surfaces as a useful qualitative guide.

Cation-pi interactions in aromatics of biological and medicinal interest: electrostatic potential surfaces as a useful qualitative guide.

London Dispersion in Molecular Chemistry—Reconsidering Steric Effects

London’sche Dispersionswechselwirkungen in der Molekülchemie – eine Neubetrachtung sterischer Effekte

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