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Gold(III) Alkyne Complexes: Bonding and Reaction Pathways
Luca Rocchigiani1, Julio Fernandez-Cestau1, Gabriele Agonigi1
1School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
Researchers synthesized and characterized novel gold(III) π-alkyne complexes, revealing key factors influencing their stability and reactivity compared to platinum(II) complexes. This work opens new avenues in gold-mediated carbon-carbon bond formation.
Area of Science:
- Organometallic Chemistry
- Gold Chemistry
- Alkyne Coordination
Background:
- Classical platinum(II) alkyne complexes are well-studied.
- Hypothetical gold(III) π-alkyne complexes present unique bonding and reactivity challenges.
Purpose of the Study:
- To synthesize and characterize novel gold(III) π-alkyne complexes.
- To elucidate the factors governing their stability and reactivity.
- To compare their behavior with platinum(II) alkyne complexes.
Main Methods:
- Synthesis of gold(III) π-alkyne complexes.
- Characterization using spectroscopic and analytical techniques.
- Computational studies on bonding and stability.
Main Results:
- Successful synthesis and characterization of hypothetical gold(III) π-alkyne complexes.
- Stability and bonding are strongly influenced by trans effect and steric factors.
- Lack of back-bonding in gold(III) complexes facilitates alkyne slippage compared to platinum(II).
Conclusions:
- Gold(III) complexes are significantly more reactive than platinum(II) congeners due to electronic and steric effects.
- The propensity of gold to facilitate C-C bond formation is explained by energetic favorability of alkyne slippage.
- A new reaction sequence involving cycloaddition, aryl migration, and reductive deprotonation in gold chemistry was demonstrated.
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