Structure, Deprotonation Energy, and Cation Affinity of an Ethynyl-Expanded Cubane

2003 ◽  
Vol 107 (24) ◽  
pp. 4957-4961 ◽  
Author(s):  
Steven M. Bachrach
Keyword(s):  
Cation Affinity ◽  
Deprotonation Energy

Methyl Cation Affinity vs Proton Affinity in Substituted Benzenes:  An ab Initio Study

1998 ◽  
Vol 102 (17) ◽  
pp. 2981-2987 ◽  
Author(s):  
Zvonimir B. Maksić ◽  
Mirjana Eckert-Maksić ◽  
Andrea Knežević
Keyword(s):  
Ab Initio ◽  
Proton Affinity ◽  
Ab Initio Study ◽  
Substituted Benzenes ◽  
Cation Affinity ◽  
Methyl Cation

scholarly journals Toward Engineering Intra-Receptor Interactions into Bis(crown ethers)

2012 ◽  
Vol 7 (3) ◽  
pp. 1934578X1200700
Author(s):  
Martin R. Krause ◽  
Stefan Kubik
Keyword(s):  
Crown Ether ◽  
Metal Ion ◽  
Hydrophobic Interactions ◽  
Titration Calorimetry ◽  
Potassium Ions ◽  
Solvent Mixtures ◽  
Binding Studies ◽  
Synthetic Receptor ◽  
Receptor Interactions ◽  
Cation Affinity

A synthetic receptor was designed in which cooperative binding of two crown ether moieties to an alkali metal ion simultaneously causes two hydrophobic substituents not involved in direct host-guest interactions to converge. Hydrophobic interactions between these substituents can be expected to contribute to the overall complex stability. Independent binding studies involving two diastereoisomers of this bis(crown ether), one in which intra-receptor interactions between the substituents are potentially possible and one in which they are not, using isothermal titration calorimetry showed that both isomers bind potassium ions in different solvent mixtures with the same overall affinity. Profound differences were observed for each isomer, however, in the enthalpies and entropies of binding, which are consistent with intra-receptor interactions in one compound. These interactions are counteracted by enthalpy-entropy compensation so that no overall improvement in cation affinity could be observed.

Ab initio and DFT cation affinity study of selected neurosteroids

2005 ◽  
Vol 723 (1-3) ◽  
pp. 85-93 ◽  
Author(s):  
Anthony A. Morrison ◽  
Mitchell C. Paul ◽  
Carl H. Parsons ◽  
Mike B. Calford ◽  
Ellak I. von Nagy-Felsobuki
Keyword(s):  
Ab Initio ◽  
Cation Affinity ◽  
Ab Initio And Dft

The Effect of Zirconium Incorporation on the Brønsted Acidity of Zeolite: A DFT Study

2010 ◽  
Vol 44-47 ◽  
pp. 3616-3619
Author(s):  
Hai Lu Zhang ◽  
An Min Zheng ◽  
Zong Wu Deng
Keyword(s):  
Molecular Sieves ◽  
Density Functional ◽  
Catalytic Mechanism ◽  
Zeolite A ◽  
Brønsted Acidity ◽  
Functional Theory ◽  
Brönsted Acidity ◽  
Free Sample ◽  
Nh3 Adsorption ◽  
Deprotonation Energy

The incorporation of zirconium atoms into the framework of some aluminosilicate molecular sieves can enhance the reactivities of some typical strong Brønsted acid needed reactions, and the strengthening of Brønsted acidity were regarded as one possible reason. In this study, the effects of zirconium incorporation on the Brønsted acidity of zeolite with CHA structure were characterized by means of periodic density functional theory (PDFT) calculations. Results from deprotonation energy and NH3 adsorption energy are consistent and show that no significant acidity enhancement is found in comparison to Zr-free sample. The results indicate new catalytic mechanism should exist.

scholarly journals The role of alkali metal cations in the stabilization of guanine quadruplexes: why K+ is the best

2016 ◽  
Vol 18 (31) ◽  
pp. 20895-20904 ◽  
Author(s):  
F. Zaccaria ◽  
G. Paragi ◽  
C. Fonseca Guerra
Keyword(s):  
Alkali Metal ◽  
Metal Ions ◽  
Metal Cations ◽  
Alkali Metal Ions ◽  
Alkali Metal Cations ◽  
Equal Importance ◽  
Cation Affinity

The desolvation and size of monovalent alkali metal ions are of equal importance for the cation affinity of guanine quadruplexes.

DFT studies of imino and thiocarbonyl ligands with the pentaaqua Mg2+ cation: affinity and associated parameters

2013 ◽  
Vol 19 (6) ◽  
pp. 2669-2677 ◽  
Author(s):  
Leonardo Moreira da Costa ◽  
Glaucio Braga Ferreira ◽  
José Walkimar de M. Carneiro
Keyword(s):  
Dft Studies ◽  
Cation Affinity
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