Related Experiment Video
Updated: Aug 29, 2025
13:21
Preparation, Purification, and Characterization of Lanthanide Complexes for Use as Contrast Agents for Magnetic Resonance Imaging
Published on: July 21, 2011
15.1K
Ligand as Buffer for Improving Chemical Stability of Coordination Polymers
Xiaomeng Jin1, Lina Zhao1, Xiaojun Zhang1
1School of Chemistry and Material Science, Heilongjiang University, Harbin 150080, P. R. China.
ACS Applied Materials & Interfaces
|September 8, 2022
Summary
This study enhances coordination polymer (CP) pH stability using ligand salt buffering sites. The novel approach extends the stability range of Eu-d-DBTA CPs from pH 6-8 to 3-11, improving their functionality.
Area of Science:
- Materials Science
- Inorganic Chemistry
- Supramolecular Chemistry
Background:
- Chemical stability, particularly in aqueous environments, is a critical challenge for coordination polymers (CPs).
- Existing technologies for protecting CPs against acidic or alkaline conditions are limited.
- Developing robust CPs is essential for advanced material applications.
Purpose of the Study:
- To develop a novel strategy for enhancing the pH stability of coordination polymers.
- To investigate the use of ligand salts as buffering sites within CP structures.
- To explore the impact of improved pH stability on the functional properties of CPs.
Main Methods:
- Synthesis of a selective one-dimensional CP, Eu-d-DBTA, using d-O,O'-dibenzoyltartaric acid (d-H2DBTA).
- Modification of the CP by introducing the ligand salt Na-d-DBTA to create buffer sites.
- Crystallographic structure analysis to elucidate the dynamic structure and buffer site formation.
- Evaluation of photoluminescence properties and selective sensing capabilities across a wide pH range.
Main Results:
- The introduction of Na-d-DBTA extended the pH stability of Eu-d-DBTA from 6-8 to 3-11.
- Crystallographic data revealed a dynamic Eu/Na-d-DBTA structure with Na-d-DBTA acting as buffer sites.
- The modified CP exhibited stable photoluminescence and selective sensing of l-tryptophan and l-lysine within the extended pH range.
- Ligand-as-buffer technology also improved pH stability in other CPs and metal-organic frameworks.
Conclusions:
- Ligand salt buffering is an effective strategy for significantly enhancing the pH stability of coordination polymers.
- The dynamic single-crystal-to-single-crystal transformation facilitates the protective buffering mechanism.
- This approach broadens the applicability of CPs in diverse aqueous environments and for sensing applications.
- The ligand-as-buffer technology offers a promising route for designing advanced inorganic-organic hybrid materials with superior functionality.
Keywords:
aqueous amino acidschemical stabilitycoordination polymerligand-as-buffer (LAB) technologyluminescence sensingMore Related Videos
Related Concept Videos
02:51Metal-Ligand Bonds
21.4K
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...
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...
21.4K
01:09Complexation Equilibria: Factors Influencing Stability of Complexes
459
In complexation reactions, metal cations are the electron pair acceptors, and the ligands are the electron pair donors. The stability of the metal complexes depends primarily on the complexing ability of the central metal ion and the nature of the ligands. Generally, the complexing ability of the metal ion depends on the size and charge of the ion. As the metal ion size increases, the stability of the metal complexes decreases, provided that the valency of the metal ion and the ligands remain...
459
01:19Complexation Equilibria: The Chelate Effect
623
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
623
00:43Complexometric Titration: Ligands
1.1K
Different monodentate and polydentate ligands are used as complexing agents in complexometric titration reactions. The formation of complexes by mono- and bidentate ligands involves two or more intermediate steps, limiting their use as complexing agents. In comparison, polydentate ligands can form complexes with metal ions in a single-step process, facilitating sharper end points. This means polydentate ligands, such as amino carboxylic acid derivatives, are most commonly employed in...
1.1K
01:22EDTA: Chemistry and Properties
2.2K
Polydentate ligands are most widely used in complexometric titrations because they form more stable complexes with the metal ions than mono- or bidentate ligands due to the chelate effect. Examples of polydentate ligands are ethylenediaminetetraacetic acid (EDTA), crown ethers, and cryptands. The most important feature of optimal polydentate ligands is the ability to form 1:1 complexes in a single-step process. Amino carboxylic acid derivatives are frequently used as complexing agents. EDTA is...
2.2K
02:54Coordination Compounds and Nomenclature
22.1K
In most main group element compounds, the valence electrons of the isolated atoms combine to form chemical bonds that satisfy the octet rule. For instance, the four valence electrons of carbon overlap with electrons from four hydrogen atoms to form CH4. The one valence electron leaves sodium and adds to the seven valence electrons of chlorine to form the ionic formula unit NaCl (Figure 1a). Transition metals do not normally bond in this fashion. They primarily form coordinate covalent bonds, a...
22.1K