Related Experiment Video
Updated: Dec 28, 2025
10:44
Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
11.4K
Tuning electronic structure through halide modulation of mesoionic carbene cobalt complexes.
Alex J Mantanona1, Daniel R Tolentino1, Kristine S Cay1
1Department of Chemistry and Biochemistry, University of California - San Diego, La Jolla, CA 92093, USA. jrinehart@ucsd.edu.
Dalton Transactions (Cambridge, England : 2003)
|February 13, 2020
Summary
The study introduces novel cobalt(II) complexes with mesoionic carbenes (MICs), revealing a unique electronic influence on tetrahedral cobalt. The findings highlight how MICs and halide ligands tune the electronic properties of these cobalt complexes.
Area of Science:
- Inorganic Chemistry
- Organometallic Chemistry
Background:
- Mesoionic carbenes (MICs) are a unique class of ligands with tunable electronic properties.
- Tetrahedral cobalt(II) complexes are important in various catalytic and magnetic applications.
Purpose of the Study:
- To synthesize and characterize the first examples of cobalt(II) complexes featuring mesoionic carbene ligands.
- To investigate the electronic effects of MIC ligands on tetrahedral cobalt(II) centers.
- To explore the influence of coordinated halides on the electronic properties of these complexes.
Main Methods:
- Synthesis of cobalt(II) complexes with MIC ligands and varying halides (Cl-, Br-, I-).
- Absorption spectroscopy to probe electronic transitions.
- Magnetometry to determine magnetic properties.
Main Results:
- Successful synthesis of novel Co(II)-MIC complexes (CoX2DippMIC2).
- Demonstration of a significant electronic perturbation induced by the MIC ligand on the tetrahedral Co(II) center.
- Analysis of the strong σ-donating and minimal π-accepting nature of the MIC ligand.
- Evidence of tunability of electronic properties by the coordinated halide (Cl-, Br-, I-).
Conclusions:
- The study presents the first Co(II) complexes with MIC ligands, expanding the scope of known MIC coordination chemistry.
- The strong σ-donating ability of MICs significantly perturbs the electronic structure of tetrahedral Co(II) complexes.
- The electronic properties of these novel complexes can be fine-tuned by modifying the halide ligand.
More Related Videos
Related Concept Videos
02:42Valence Bond Theory
10.9K
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...
10.9K
02:58Crystal Field Theory - Octahedral Complexes
30.1K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
30.1K
03:02Colors and Magnetism
13.6K
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...
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...
13.6K
02:34Structural Isomerism
21.4K
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...
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...
21.4K
02:46Halogenation of Alkenes
18.2K
Halogenation is the addition of chlorine or bromine across the double bond in an alkene to yield a vicinal dihalide. The reaction occurs in the presence of inert and non-nucleophilic solvents, such as methylene chloride, chloroform, or carbon tetrachloride.
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.
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.
18.2K
01:23Properties of Organometallic Compounds
1.5K
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.
1.5K