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Updated: Jun 22, 2026

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Trisilyl-substituted vinyl cations
Andrea Klaer1, Yvonne Syha2, Hamid Reza Nasiri3
1Institut für Reine und Angewandte Chemie, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky Strasse 9-11, 26211 Oldenburg (Germany).
Researchers synthesized novel vinyl cations with silyl and germyl groups. These cations exhibit dynamic structures and intramolecular exchange processes, offering insights into protonated acetylene chemistry.
Area of Science:
- Organosilicon Chemistry
- Carbocation Chemistry
- Organic Synthesis
Background:
- Vinyl cations are reactive intermediates crucial in organic synthesis.
- Understanding the electronic and structural properties of substituted vinyl cations is key to controlling reactivity.
- Silyl and germyl substituents can significantly influence carbocation stability and dynamics.
Purpose of the Study:
- To synthesize and characterize novel beta,beta-disilyl-substituted vinyl cations.
- To investigate the structural dynamics and exchange processes in these unique carbocations.
- To compare the behavior of silyl- and germyl-substituted vinyl cations with known systems.
Main Methods:
- Preparation of vinyl cations via intramolecular addition of silylium ions to alkynes.
- Isolation of vinyl cations as tetrakis(pentafluorophenyl) borate salts.
- Characterization using Nuclear Magnetic Resonance (NMR) spectroscopy, including (13)C and (29)Si NMR.
- Employing doubly (13)C-labeled compounds to elucidate reaction mechanisms.
Main Results:
- Successfully synthesized and isolated a series of beta,beta-disilyl-substituted vinyl cations with varying substituents.
- NMR data revealed highly dynamic structures for beta,beta-disilyl-alpha-germyl and trisilyl-substituted vinyl cations.
- An intramolecular exchange process, fast on the NMR timescale at room temperature, was observed.
- A mechanism involving rotation of the dicarbyne unit within a triangular silyl fragment framework was proposed.
Conclusions:
- The dynamic behavior of these novel vinyl cations provides a parallel to the known structure of protonated acetylene.
- The findings offer new insights into the electronic effects and structural flexibility imparted by silyl and germyl groups in carbocations.
- This study expands the understanding of vinyl cation chemistry and opens avenues for designing new organosilicon compounds.
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