Related Experiment Video
Updated: Jun 26, 2026

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
Published on: July 27, 2022
Chelation-assisted carbon-halogen bond activation by a rhodium(I) complex
Shanshan Chen1, Yongxin Li, Jing Zhao
1Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371.
Rhodium complexes activate C-X bonds for C-H activation, forming cationic monohalide and neutral dihalide complexes. Dihalide complexes catalyze alkyne dimerization, while monohalides are inactive.
Area of Science:
- Organometallic Chemistry
- Coordination Chemistry
- Catalysis
Background:
- C-X bond activation is crucial for functionalization.
- Rhodium complexes are versatile catalysts.
- Cyclometalation offers unique ligand architectures.
Purpose of the Study:
- To investigate chelation-assisted C-X bond activation by rhodium.
- To synthesize novel rhodium(III) halide complexes.
- To evaluate catalytic activity of synthesized complexes.
Main Methods:
- Reaction of [Rh(PPh3)2(acetone)2]+ with halophenylpyridine/halobenzquinoline.
- Thermal treatment of cationic rhodium complexes.
- Synthesis of rhodium and iridium diiodides from hydrides.
- X-ray crystallography for structural characterization.
Main Results:
- Synthesis of 16-electron cationic rhodium(III) monohalide complexes.
- Formation of neutral octahedral rhodium(III) dihalide complexes.
- Alternative synthesis of rhodium and iridium diiodides.
- Structural characterization of key complexes.
- Rhodium(III) dihalides catalyze alkyne dimerization.
Conclusions:
- Chelation-assisted C-X bond activation is effective for rhodium complex synthesis.
- Rhodium(III) dihalide complexes are active alkyne dimerization catalysts.
- 16-electron cationic rhodium(III) monohalides show no catalytic activity.
More Related Videos
10:39Heterogeneous Removal of Water-Soluble Ruthenium Olefin Metathesis Catalyst from Aqueous Media Via Host-Guest Interaction
Published on: August 23, 2018
10:42Combining Solid-state and Solution-based Techniques: Synthesis and Reactivity of Chalcogenidoplumbates(II or IV)
Published on: December 29, 2016
Related Concept Videos
Complexation Equilibria: The Chelate Effect
Metal-Ligand Bonds
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...
Halogenation of Alkenes
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...
ortho–para-Directing Deactivators: Halogens
Electrophilic Addition to Alkynes: Hydrohalogenation