NHC-Supported 2-Sila and 2-Germavinylidenes: Synthesis, Dynamics, First Reactivity and Theoretical Studies
Sandeep Kumar1, Leonard R Maurer1, Gregor Schnakenburg1
1Institut für Anorganische Chemie, Universität Bonn, Gerhard-Domagk-Str. 1, 53121, Bonn, Germany.
Angewandte Chemie (International Ed. in English)
|February 6, 2024
Summary
Researchers synthesized and studied novel N-heterocyclic carbene (NHC)-supported 2-silavinylidene and 2-germavinylidene compounds. These findings open new avenues for exploring tetrelavinylidene chemistry and its synthetic applications.
Area of Science:
- Organometallic Chemistry
- Main Group Chemistry
- Carbene Chemistry
Background:
- 2-tetrelavinylidenes are theoretically predicted to be unstable isomers.
- Experimental studies on 2-tetrelavinylidenes and their derivatives are scarce due to their instability.
- N-heterocyclic carbenes (NHCs) are versatile ligands in stabilizing reactive species.
Purpose of the Study:
- To experimentally synthesize and characterize the first NHC-supported 2-silavinylidene and 2-germavinylidene compounds.
- To investigate the electronic structure, bonding, and dynamic properties of these novel tetrelavinylidenes.
- To explore the synthetic utility of these compounds in generating new organometallic species.
Main Methods:
- Synthesis of NHC-supported 2-silavinylidene and 2-germavinylidene from 1,2-dibromoditetrelenes using a diazoolefin transfer reagent.
- Detailed structural and electronic characterization using X-ray diffraction, NMR spectroscopy, and quantum chemical calculations.
- Investigation of dynamic behavior through NMR studies, focusing on NHC rotation.
Main Results:
- Successful synthesis of the first NHC-supported 2-silavinylidene and 2-germavinylidene compounds.
- Characterization revealed a planar vinylidene core, a bent dicoordinated vinylidene carbon, a short E=C bond, and an orthogonal NHC orientation.
- Electronic structure analysis indicated significant bent 1-tetrelaallene and tetrelyne character.
- NMR studies showed low activation barriers for NHC rotation.
- Demonstrated synthetic potential through the preparation of unprecedented NHC-supported bromogermynes.
Conclusions:
- The study provides the first experimental evidence and characterization of stable NHC-supported 2-tetrelavinylidenes.
- These compounds exhibit unique structural and electronic properties, challenging previous assumptions about their stability.
- The successful synthesis of bromogermynes highlights the synthetic versatility of these novel tetrelavinylidene complexes.
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