Direct Insight into the Ion Pair Equilibria of Lithium Organocuprates by1H,6Li HOESY Experiments

2000 ◽  
Vol 19 (15) ◽  
pp. 2868-2873 ◽  
Author(s):  
Ruth M. Gschwind ◽  
Pattuparambil R. Rajamohanan ◽  
Michael John ◽  
Gernot Boche
Keyword(s):  
Ion Pair ◽  
Insight Into

Computational insight into the cooperative role of non-covalent interactions in the aza-Henry reaction catalyzed by quinine derivatives: mechanism and enantioselectivity

2016 ◽  
Vol 14 (40) ◽  
pp. 9588-9597 ◽  
Author(s):  
Yunsheng Xue ◽  
Yuhui Wang ◽  
Zhongyan Cao ◽  
Jian Zhou ◽  
Zhao-Xu Chen
Keyword(s):  
Hydrogen Bonding ◽  
Dft Calculations ◽  
Ion Pair ◽  
Henry Reaction ◽  
Brönsted Acid ◽  
Non Covalent Interactions ◽  
Dual Activation ◽  
Covalent Interactions ◽  
Insight Into

DFT calculations reveal the viability of the two possible ion pair-hydrogen bonding and Brønsted acid-hydrogen bonding dual activation modes.

Chloride-dependent conformational changes in the GlyT1 glycine transporter

2020 ◽  
Author(s):  
Yuan-Wei Zhang ◽  
Stacy Uchendu ◽  
Vanessa Leone ◽  
Richard T. Bradshaw ◽  
Ntumba Sangwa ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Ion Pair ◽  
Cysteine Residues ◽  
Glycine Transporter ◽  
Open Conformation ◽  
Transporter Family ◽  
Transport Cycle ◽  
Dynamics Simulations ◽  
Insight Into

AbstractThe human GlyT1 glycine transporter requires chloride for its function. However, the mechanism by which Cl- exerts its influence is unknown. To examine the role that Cl- plays in the transport cycle, we measured the effect of Cl- on both glycine binding and conformational changes. The ability of glycine to displace the high-affinity radioligand [3H]CHIBA-3007 required Na+ and was potentiated over 1000-fold by Cl-. We generated GlyT1b mutants containing reactive cysteine residues in either the extracellular or cytoplasmic permeation pathways and measured changes in the reactivity of those cysteine residues as indicators of conformational changes in response to ions and substrate. Na+ increased accessibility in the extracellular pathway and decreased it in the cytoplasmic pathway, consistent with stabilizing an outward-open conformation as observed in other members of this transporter family. In the presence of Na+, both glycine and Cl- independently shifted the conformation of GlyT1b toward an outward-closed conformation. Together, Na+, glycine and Cl- stabilized an inward-open conformation of GlyT1b. We then examined whether Cl- acts by interacting with a conserved glutamine to allow formation of an ion pair that stabilizes the closed state of the extracellular pathway. Molecular dynamics simulations of a GlyT1 homologue indicated that this ion pair is formed more frequently as that pathway closes. Mutation of the glutamine blocked the effect of Cl-, and substituting it with glutamate or lysine resulted in outward- or inward-facing transporter conformations, respectively. These results provide novel and unexpected insight into the role of Cl- in this family of transporters.

scholarly journals Analysis of long dsRNA produced in vitro and in vivo using atomic force microscopy in conjunction with ion-pair reverse-phase HPLC

The Analyst ◽  
2019 ◽  
Vol 144 (16) ◽  
pp. 4985-4994
Author(s):  
Alison O. Nwokeoji ◽  
Sandip Kumar ◽  
Peter M. Kilby ◽  
David E. Portwood ◽  
Jamie K. Hobbs ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
High Performance ◽  
Ion Pair ◽  
Reverse Phase Hplc ◽  
Reverse Phase ◽  
Force Microscopy ◽  
Atomic Force ◽  
Insight Into

Atomic force microscopy (AFM) in conjunction with ion-pair reverse-phase high performance liquid chromatography (IP-RP-HPLC) provides novel insight into dsRNA for RNAi applications.

The Structure of Imidazolium-Based Ionic Liquids: Insights From Ion-Pair Interactions

2007 ◽  
Vol 60 (1) ◽  
pp. 9 ◽  
Author(s):  
Patricia A. Hunt ◽  
Ian R. Gould ◽  
Barbara Kirchner
Keyword(s):  
Ionic Liquids ◽  
Melting Point ◽  
Ion Pairs ◽  
Liquid Structure ◽  
High Viscosity ◽  
Ion Pair ◽  
Low Viscosity ◽  
Association Energy ◽  
Dynamics Simulations ◽  
Insight Into

A large number of ab-initio (B3LYP/6–31++G(d,p)) computed ion-pair structures have been examined in order to determine if such calculations are capable of offering insight into the physical properties of the liquid state, particularly viscosity and melting point. Ion pairings based around the 1-butyl-3-methylimidazolium (C4C1im) cations and a range of anions (Cl, BF4, and N(Tf)2 where N(Tf)2 is bis(trifluoromethylsulfonly)imide) were chosen because of the range of viscosities exhibited by the corresponding ionic liquids. We have used these results to build up a ‘picture’ of the ionic liquid structure which is consistent with molecular dynamics simulations and experimental evidence. However, further work is required to established if such an analysis could be predictive. Nevertheless, we establish clear relationships relating ion-pair association energy, a derived ‘connectivity index’, and the diversity of structures with viscosity and melting point. Our calculations indicate that ions in C4C1imCl form a strong, highly connected and regular array thus rationalizing the high viscosity and melting point. In contrast the ion-pairs of C4C1imN(Tf)2 form a weakly interacting, highly disordered, and low connectivity network consistent with the low viscosity and melting point. C4C1imBF4 lies midway between these two extremes.

scholarly journals Chloride-dependent conformational changes in the GlyT1 glycine transporter

2021 ◽  
Vol 118 (10) ◽  
pp. e2017431118 ◽  
Author(s):  
Yuan-Wei Zhang ◽  
Stacy Uchendu ◽  
Vanessa Leone ◽  
Richard T. Bradshaw ◽  
Ntumba Sangwa ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Ion Pair ◽  
Cysteine Residues ◽  
Glycine Transporter ◽  
Open Conformation ◽  
Transporter Family ◽  
Transport Cycle ◽  
Dynamics Simulations ◽  
Insight Into

The human GlyT1 glycine transporter requires chloride for its function. However, the mechanism by which Cl− exerts its influence is unknown. To examine the role that Cl− plays in the transport cycle, we measured the effect of Cl− on both glycine binding and conformational changes. The ability of glycine to displace the high-affinity radioligand [3H]CHIBA-3007 required Na+ and was potentiated over 1,000-fold by Cl−. We generated GlyT1b mutants containing reactive cysteine residues in either the extracellular or cytoplasmic permeation pathways and measured changes in the reactivity of those cysteine residues as indicators of conformational changes in response to ions and substrate. Na+ increased accessibility in the extracellular pathway and decreased it in the cytoplasmic pathway, consistent with stabilizing an outward-open conformation as observed in other members of this transporter family. In the presence of Na+, both glycine and Cl− independently shifted the conformation of GlyT1b toward an outward-closed conformation. Together, Na+, glycine, and Cl− stabilized an inward-open conformation of GlyT1b. We then examined whether Cl− acts by interacting with a conserved glutamine to allow formation of an ion pair that stabilizes the closed state of the extracellular pathway. Molecular dynamics simulations of a GlyT1 homolog indicated that this ion pair is formed more frequently as that pathway closes. Mutation of the glutamine blocked the effect of Cl−, and substituting it with glutamate or lysine resulted in outward- or inward-facing transporter conformations, respectively. These results provide an unexpected insight into the role of Cl− in this family of transporters.

Thermodynamic evidence for K+–SO42− ion pair formation on Pt(111). New insight into cation specific adsorption

2010 ◽  
Vol 12 (38) ◽  
pp. 12146 ◽  
Author(s):  
Nuria Garcia-Araez ◽  
Victor Climent ◽  
Paramaconi Rodriguez ◽  
Juan M. Feliu
Keyword(s):  
Ion Pair ◽  
Pair Formation ◽  
Specific Adsorption ◽  
Ion Pair Formation ◽  
Insight Into

Computational Insight into Calcium–Sulfate Ion Pair Formation

2017 ◽  
Vol 121 (46) ◽  
pp. 25956-25966 ◽  
Author(s):  
Emily H. Byrne ◽  
Paolo Raiteri ◽  
Julian D. Gale
Keyword(s):  
Calcium Sulfate ◽  
Ion Pair ◽  
Pair Formation ◽  
Sulfate Ion ◽  
Ion Pair Formation ◽  
Insight Into
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