Related Experiment Video
Updated: Jul 13, 2026
06:40
Synthesis of a Water-soluble Metal–Organic Complex Array
Published on: October 8, 2016
Cationic assembly of metal complex aggregates: structural diversity, solution stability, and magnetic properties
Xiang Lin1, Dan M J Doble, Alexander J Blake
1School of Chemistry, The University of Nottingham, University Park, Nottingham NG7 2RD, UK.
Journal of the American Chemical Society
|August 2, 2003
Summary
This study details the creation of novel metal-organic cage compounds using nickel(II) complexes templated by various metal cations. These cages exhibit tunable structures and magnetic properties, offering insights into coordination chemistry.
Area of Science:
- Coordination Chemistry
- Supramolecular Chemistry
- Materials Science
Background:
- The synthesis of complex metal-organic structures is crucial for developing new functional materials.
- Tetradentate imino-carboxylate ligands offer versatile coordination capabilities for metal ions.
Purpose of the Study:
- To synthesize and characterize novel metal-organic cage compounds using a nickel(II) complex and various templating metal ions.
- To investigate the structural diversity and stability of these cage aggregates.
- To explore the magnetic properties of the assembled cage structures.
Main Methods:
- Complexation of Ni(II) with a tetradentate imino-carboxylate ligand ([L](2-)).
- Templated self-assembly of nickel-ligand fragments using lanthanide, Group II, and Group I metal cations.
- Structural characterization using X-ray crystallography (implied by compound descriptions).
- Stability analysis via electronic spectroscopy and mass spectrometry.
- Magnetic susceptibility measurements.
Main Results:
- Formation of octahedral cage aggregates (M[Ni(L)](6))(x)(+) templated by lanthanide and Group II ions (M = Sr(II), Ba(II), La(III), Ce(III), Pr(III), Nd(III)).
- Assembly of diverse cage structures templated by Group I cations (Na(+), Li(+)) and alkali metal-oxide cores ([Na(5)O](3+), [Na(3)Li(2)O](3+), [Li(4)O](2+)).
- Observation of a Cs(+)-templated cluster and a monomeric Ni(II) complex.
- Stability trend determined as 1-6 > 7 > 8 ≈ 9.
- Evidence of net antiferromagnetic exchange between magnetic centers within the cages.
Conclusions:
- The choice of templating metal cation dictates the architecture and composition of the resulting metal-organic cages.
- The synthesized cage compounds display varying degrees of stability in solution.
- Antiferromagnetic interactions are present within the assembled nickel-containing cage structures.
More Related Videos
08:55Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
06:53Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
Related Concept Videos
02:32Bonding in Metals
Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Drüde called the “Electron Sea Model”.
02:37Metallic Solids
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
02:42Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
03:02Colors and Magnetism
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
01:19Complexation Equilibria: The Chelate Effect
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...
01:09Complexation Equilibria: Factors Influencing Stability of Complexes
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...