Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Ion Exchange01:17

Ion Exchange

Ion exchange chromatography separates charged molecules from a solution by reversibly exchanging them with mobile, or 'active', ions associated with the oppositely charged stationary phase. This method can be used to separate ions, soften and deionize water, and purify solutions. The polymers comprising the ion-exchange column are high-molecular-weight and chemically stable polymers, crosslinked to be porous and essentially insoluble. They are also functionalized with either acidic or basic...
Metal-Ligand Bonds02:51

Metal-Ligand Bonds

The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
Complexation Equilibria: Overview01:23

Complexation Equilibria: Overview

Complexation reactions take place when dative or coordinate covalent bonds form between metal ions and ligands. The compounds formed in these reactions are called coordination compounds. The number of bonds formed between the metal ion and the ligands is called its coordination number. Generally, most metal ions in an aqueous solution are solvated by water molecules and thus exist as aqua complexes.
The equilibrium constant of the complexation reaction is represented as the formation constant...
Ion-Exchange Chromatography01:09

Ion-Exchange Chromatography

Ion-exchange chromatography, or IEC, is a technique for separating ions based on their affinity for the stationary phase. The stationary phase is a cross-linked polymer resin with covalently attached ionic functional groups. The functional groups can be either positively charged (cation exchangers) or negatively charged (anion exchangers). A cation exchanger consists of a polymeric anion and active cations, while an anion exchanger is a polymeric cation with active anions. The choice of...
Extraction: Advanced Methods00:56

Extraction: Advanced Methods

Metal ions can be separated from one another by complexation with organic ligands–the chelating agent– to form uncharged chelates. Here, the chelating agent must contain hydrophobic groups and behave as a weak acid, losing a proton to bind with the metal. Since most organic ligands used in this process are insoluble or undergo oxidation in the aqueous phase, the chelating agent is initially added to the organic phase and extracted into the aqueous phase. The metal-ligand complex is formed in...
Formation of Complex Ions03:45

Formation of Complex Ions

A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

When can AlphaFold predict the oligomeric states of proteins?

Protein science : a publication of the Protein Society·2026
Same author

Bacterial lipids traverse the hydrophobic groove of TamB.

Biophysical journal·2026
Same author

The <i>Plasmodium falciparum</i> PPCS is a unique heteromeric complex with prokaryote-like activity and is a target of pantothenate analogs.

Science advances·2026
Same author

Periodic Hirshfeld Atom Refinement.

The journal of physical chemistry letters·2026
Same author

2'-O-Methyl-guanosine RNA fragments antagonize TLR7 and TLR8 to limit autoimmunity.

Nature immunology·2026
Same author

TMEM63 proteins act as mechanically activated cholesterol modulated lipid scramblases contributing to membrane mechano-resilience.

Nature communications·2026
Same journal

Optimizing grid preparation methods for TEM imaging of amyloid-forming proteins.

Biophysical chemistry·2026
Same journal

Biogenic reduction mechanisms in iron oxide nanoparticle synthesis: Strategies to mitigate microbial resistance.

Biophysical chemistry·2026
Same journal

Novel Pennisetum Alopecuroides-derived activated carbon for high-efficiency Tartrazine Removal: Box-Behnken optimization and DFT-assisted mechanistic insights.

Biophysical chemistry·2026
Same journal

Reactive molecular dynamics investigation of the first steps of coronavirus (COVID-19) viral-protein ligands fragment (SARS-CoV-2).

Biophysical chemistry·2026
Same journal

Probing the interactions between bovine hemoglobin and three berberine saturated fatty acid salts by multi-spectral techniques, conductimetry and molecular docking.

Biophysical chemistry·2026
Same journal

Insights from NMR - based metabolomics elucidates key metabolic dysregulation in pancreatitis-induced acute respiratory distress syndrome: A step towards precision medicine.

Biophysical chemistry·2026
See all related articles

Related Experiment Video

Updated: May 15, 2026

Merging Ion Concentration Polarization between Juxtaposed Ion Exchange Membranes to Block the Propagation of the Polarization Zone
08:06

Merging Ion Concentration Polarization between Juxtaposed Ion Exchange Membranes to Block the Propagation of the Polarization Zone

Published on: February 23, 2017

How does overcoordination create ion selectivity?

Michael Thomas1, Dylan Jayatilaka, Ben Corry

  • 1Research School of Biology, The Australian National University, Canberra, Australia.

Biophysical Chemistry
|January 23, 2013
PubMed
Summary
This summary is machine-generated.

Biological molecules achieve ion selectivity by controlling ion coordination numbers. Smaller ions show unique geometric changes with added ligands, explaining selectivity via overcoordination, unlike larger ions.

More Related Videos

Double-barreled and Concentric Microelectrodes for Measurement of Extracellular Ion Signals in Brain Tissue
11:08

Double-barreled and Concentric Microelectrodes for Measurement of Extracellular Ion Signals in Brain Tissue

Published on: September 5, 2015

Whole-cell Patch-clamp Recordings for Electrophysiological Determination of Ion Selectivity in Channelrhodopsins
08:39

Whole-cell Patch-clamp Recordings for Electrophysiological Determination of Ion Selectivity in Channelrhodopsins

Published on: May 22, 2017

Related Experiment Videos

Last Updated: May 15, 2026

Merging Ion Concentration Polarization between Juxtaposed Ion Exchange Membranes to Block the Propagation of the Polarization Zone
08:06

Merging Ion Concentration Polarization between Juxtaposed Ion Exchange Membranes to Block the Propagation of the Polarization Zone

Published on: February 23, 2017

Double-barreled and Concentric Microelectrodes for Measurement of Extracellular Ion Signals in Brain Tissue
11:08

Double-barreled and Concentric Microelectrodes for Measurement of Extracellular Ion Signals in Brain Tissue

Published on: September 5, 2015

Whole-cell Patch-clamp Recordings for Electrophysiological Determination of Ion Selectivity in Channelrhodopsins
08:39

Whole-cell Patch-clamp Recordings for Electrophysiological Determination of Ion Selectivity in Channelrhodopsins

Published on: May 22, 2017

Area of Science:

  • Biochemistry
  • Computational Chemistry
  • Physical Chemistry

Background:

  • Biological molecules selectively bind ions, often by enforcing specific coordination numbers.
  • The mechanism of 'overcoordination' is proposed for ion selectivity but lacks microscopic understanding.

Purpose of the Study:

  • To investigate the microscopic underpinnings of ion selectivity by overcoordination.
  • To systematically examine how ligand number affects ion-ligand and ligand-ligand interactions and thermodynamic ion selectivity.

Main Methods:

  • Utilized molecular-dynamics simulations.
  • Investigated model systems with three ions (Li+, Na+, K+) and three ligands (water, formaldehyde, formamide).

Main Results:

  • Ligand-ligand repulsion was identified as the key factor controlling system geometry with varying ligand numbers.
  • Smaller ions (Li+) demonstrated anomalous geometrical changes with additional ligands, while larger ions (Na+, K+) did not.

Conclusions:

  • Overcoordination achieves ion selectivity through differential geometric responses of ions to ligand addition.
  • The findings provide a microscopic explanation for how ion selectivity is achieved by controlling coordination numbers.