Related Experiment Video
Updated: Jul 13, 2026
08:25
Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks (MOFs)
Published on: January 17, 2020
Homochiral H-bonded proline based metal organic frameworks
Michael J Ingleson1, John Bacsa, Matthew J Rosseinsky
1Department of Chemistry, University of Liverpool, Liverpool, UK L69 7ZD.
Chemical Communications (Cambridge, England)
|July 20, 2007
Summary
Two L-proline frameworks show different metal binding based on amino acid protonation. This influences whether the amine nitrogen binds to the metal, impacting framework structure.
Area of Science:
- Coordination Chemistry
- Materials Science
- Crystallography
Background:
- Homochiral frameworks are crucial in asymmetric synthesis and chiral recognition.
- L-proline is a versatile chiral building block for constructing metal-organic frameworks.
- Understanding metal-ligand interactions is key to designing functional porous materials.
Purpose of the Study:
- To synthesize and characterize two distinct L-proline-based homochiral frameworks.
- To investigate the influence of L-proline protonation on its coordination behavior within the frameworks.
- To elucidate the relationship between binding modes and framework topology.
Main Methods:
- Solvothermal synthesis and diffusion crystallization techniques were employed.
- Single-crystal X-ray diffraction was used for structural determination.
- Infrared spectroscopy was utilized to assess the protonation state of L-proline.
Main Results:
- Two homochiral frameworks were successfully synthesized, exhibiting different L-proline coordination modes.
- Framework 1 features N,O chelating L-proline, while Framework 2 shows O,O bridging L-proline with unbound amine nitrogen.
- The distinct binding modes are directly correlated with the degree of L-proline protonation.
Conclusions:
- The coordination mode of L-proline in homochiral frameworks is controllable via its protonation state.
- This control allows for the rational design of frameworks with specific topologies and properties.
- The findings provide insights into the fundamental coordination chemistry of amino acids in metal-organic materials.
Related Concept Videos
01:23Properties of Organometallic Compounds
Organometallic compounds are compounds that contain a carbon–metal bond. Carbon belongs to an organyl group like alkyl, aryl, allyl, or benzyl groups. The metal can be from Group I or Group II of the periodic table, a transition metal, or a semimetal.
02:51Metal-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...
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...
02:06Newman Projections
Different notations are used to represent the three-dimensional structure of molecules on two-dimensional surfaces. One of the most commonly used representations is the dash-wedge formula. The dashed wedges, solid wedges, and the plane lines indicate the groups situated behind the plane, coming out of the plane, and in the plane, respectively.
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as conformers.
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as conformers.
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...
02:34Structural Isomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
02:05Prochirality
The concept of prochirality leads to the nomenclature of the individual faces of a molecule and plays a crucial role in the enantioselective reaction. It is a concept where two or more achiral molecules react to produce chiral products. A typical process is the reaction of an achiral ketone to generate a chiral alcohol. Here, the achiral reactant reacts with an achiral reducing agent, sodium borohydride, to generate an equimolar mixture of the chiral enantiomers of the product. For example, an...