Related Experiment Video
Updated: Jan 19, 2026
08:42
Metal-Ligand Coordination Complex
Published on: April 30, 2023
95.3K
Unusual η1 -Coordinated Alkyne and Alkene Complexes
Longfei Li1,2, Mengxian Dong1, Hua-Jie Zhu1
1Key Laboratory of Pharmaceutical Quality Control of Hebei Province, College of Pharmaceutical Sciences, Hebei University, Baoding, 071002, P. R. China.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|September 14, 2019
Summary
An unusual η1-coordinated alkyne complex is key to the 1-pentyne 1,1-diboration reaction. This finding, driven by Lewis acidity and steric effects, may also advance olefin polymerization.
Area of Science:
- Organometallic Chemistry
- Catalysis
Background:
- The 1,1-diboration of alkynes is a synthetically valuable transformation.
- Understanding the mechanistic pathways of organometallic reactions is crucial for catalyst design.
Purpose of the Study:
- To elucidate the mechanism of the 1-pentyne 1,1-diboration reaction.
- To investigate the role of unusual η1-coordinated alkyne complexes in this transformation.
Main Methods:
- Mechanistic study using comparative analyses.
- Computational predictions for analogous complexes.
Main Results:
- An unusual η1-coordinated alkyne complex was identified as critical for the 1-pentyne 1,1-diboration reaction.
- A "pull-push" antagonistic effect, involving Lewis acidity and steric congestion, explains the stability of η1-coordinated alkyne complexes.
- Analogous η1-coordinated alkene complexes were computationally predicted.
Conclusions:
- The η1-coordinated alkyne complex plays a pivotal role in the 1-pentyne 1,1-diboration reaction.
- The "pull-push" effect is a key factor in stabilizing these unusual coordination modes.
- Predicted η1-coordinated alkene complexes show potential for olefin polymerization applications.
Related Concept Videos
08:42Coordination Chemistry Complexes
95.3K
Source: Laboratory of Dr. Neal Abrams — SUNY College of Environmental Science and Forestry
Transition metals are found everywhere from vitamin supplements to electroplating baths. Transition metals also make up the pigments in many paints and compose all minerals. Typically, transition metals are found in the cationic form since they readily oxidize, or lose electrons, and are surrounded by electron donors called ligands. These ligands do not form ionic or covalent bonds with the metal...
Transition metals are found everywhere from vitamin supplements to electroplating baths. Transition metals also make up the pigments in many paints and compose all minerals. Typically, transition metals are found in the cationic form since they readily oxidize, or lose electrons, and are surrounded by electron donors called ligands. These ligands do not form ionic or covalent bonds with the metal...
95.3K
01:33Preparation of Aldehydes and Ketones from Alcohols, Alkenes, and Alkynes
5.2K
Aldehydes and ketones are prepared from alcohols, alkenes, and alkynes via different reaction pathways. Alcohols are the most commonly used substrates for synthesizing aldehydes and ketones. The conversion of alcohol to aldehyde, which involves the oxidation process, depends on the class of the alcohol used and the strength of the oxidizing agent. For instance, primary alcohol will form an aldehyde when treated with a weak oxidizing agent; however, it gets over-oxidized to a carboxylic acid in...
5.2K
06:52Ozonolysis of Alkenes
68.7K
Source: Vy M. Dong and Zhiwei Chen, Department of Chemistry, University of California, Irvine, CA
This experiment will demonstrate an example of an ozonolysis reaction to synthesize vanillin from isoeugenol (Figure 1). Ozonolysis of alkenes, an oxidation reaction between ozone and an alkene, is a common method to prepare aldehydes, ketones, and carboxylic acids. This experiment also demonstrates the use of an ozone generator and a low temperature (−78 °C) reaction.
This experiment will demonstrate an example of an ozonolysis reaction to synthesize vanillin from isoeugenol (Figure 1). Ozonolysis of alkenes, an oxidation reaction between ozone and an alkene, is a common method to prepare aldehydes, ketones, and carboxylic acids. This experiment also demonstrates the use of an ozone generator and a low temperature (−78 °C) reaction.
68.7K
02:10Reduction of Alkynes to trans-Alkenes: Sodium in Liquid Ammonia
10.5K
Alkynes can be reduced to trans-alkenes using sodium or lithium in liquid ammonia. The reaction, known as dissolving metal reduction, proceeds with an anti addition of hydrogen across the carbon–carbon triple bond to form the trans product. Since ammonia exists as a gas (bp = −33°C) at room temperature, the reaction is carried out at low temperatures using a mixture of dry ice (sublimes at −78°C) and acetone.
When dissolved in liquid ammonia, an alkali metal, such as sodium,...
When dissolved in liquid ammonia, an alkali metal, such as sodium,...
10.5K
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
9.0K
Introduction
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
9.0K
01:16Unusual Results
3.7K
Unusual results are those that have a very low chance of occurring. Unusual results can be identified using probabilities and the range rule of thumb. In problems involving probability, unusual results can be observed in 2 instances – an unusually high number of successes or an unusually low number of successes.
According to the range rule of thumb, any value above or below two standard deviations, 2σ from the mean, μ is considered unusual.
Maximum unusual value =...
According to the range rule of thumb, any value above or below two standard deviations, 2σ from the mean, μ is considered unusual.
Maximum unusual value =...
3.7K