Related Experiment Video
Updated: May 30, 2026
10:52
Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
Published on: July 27, 2022
Dipyrrinphenol-Mn(III) complex: synthesis, electrochemistry, spectroscopic characterisation and reactivity
Sanae El Ghachtouli1, Karolina Wójcik, Laurent Copey
1Institut de Chimie Moléculaire et des Matériaux d'Orsay, UMR-CNRS 8182, Université de Paris-Sud XI, F-91405, Orsay, France.
Dalton Transactions (Cambridge, England : 2003)
|August 16, 2011
Summary
Researchers developed a novel manganese complex featuring a unique trianionic ligand, pentafluorophenyldipyrrinphenol (DPPH(3)). This complex shows promise as a catalyst for oxygen-atom-transfer reactions, specifically epoxidation.
Area of Science:
- Organometallic Chemistry
- Catalysis
- Coordination Chemistry
Background:
- Manganese complexes are investigated for catalytic applications.
- Novel ligand design is crucial for tuning metal complex properties.
Purpose of the Study:
- To synthesize and characterize a novel manganese complex with a trianionic ligand.
- To explore the electrochemical and magnetic properties of the complex.
- To evaluate the catalytic activity of the complex in epoxidation reactions.
Main Methods:
- Synthesis of the manganese complex with pentafluorophenyldipyrrinphenol (DPPH(3)) ligand.
- X-ray crystallography for structural determination.
- Electrochemical studies (cyclic voltammetry).
- Electron Paramagnetic Resonance (EPR) spectroscopy.
- Catalytic testing for epoxidation using iodosylbenzene (PhIO).
Main Results:
- The Mn(III) complex was successfully synthesized and characterized.
- X-ray structure revealed a dimeric form in the solid state.
- Electrochemical studies showed two quasi-reversible one-electron oxidation processes.
- EPR data indicated a mononuclear Mn complex with an S = 3/2 spin system in solution.
- Preliminary epoxidation studies suggest catalytic activity via oxygen-atom-transfer (OAT).
Conclusions:
- A novel manganese complex with a trianionic DPPH(3) ligand was prepared.
- The complex exhibits interesting structural, electrochemical, and magnetic properties.
- The manganese complex demonstrates potential as a catalyst for OAT reactions, particularly epoxidation.
More Related Videos
Related Concept Videos
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.
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...
00:39Complexometric Titration: Overview
Complexometric titration involves the formation of a complex by reacting a metal ion with one or more ligands. A visual indicator often detects the end point of a complexometric titration. It is added to the metal solution before the titration, forming a stable metal–indicator complex and imparting color to the solution. As the titration approaches the equivalence point, the excess of the added ligand displaces the indicator from the metal–indicator complex, releasing the free indicator. The...
01:22EDTA: Chemistry and Properties
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...
03:45Formation 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...
01:26EDTA: Auxiliary Complexing Reagents
EDTA titrations are usually carried out in highly basic conditions, where the fully deprotonated form of EDTA, Y4−, actively complexes with the free metal ions in the solution. Several metal ions precipitate as hydrous oxide (hydroxides, oxides, or oxyhydroxides) under these conditions, lowering the concentration of free metal ions in the solution. For this reason, auxiliary complexing agents or ligands such as ammonia, tartrate, citrate, or triethanolamine are used in EDTA titrations to...