Small molecule activation: SbF3 auto-ionization supported by transfer and mesoionic NHC rearrangement
Blaž Alič1, Aleš Štefančič1, Gašper Tavčar1
1Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia. gasper.tavcar@ijs.si and Jožef Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana, Slovenia.
Dalton Transactions (Cambridge, England : 2003)
|February 24, 2017
Summary
Antimony trifluoride (SbF3) auto-ionization was achieved in non-polar solvents via a novel N-heterocyclic carbene (NHC) ligand. This process involves NHC rearrangement and facilitates SbF3 reactivity, yielding a unique pnictogen(III) halide auto-ionization product.
Area of Science:
- Inorganic Chemistry
- Organometallic Chemistry
- Materials Science
Background:
- Antimony trifluoride (SbF3) exhibits limited solubility and reactivity in non-polar aprotic solvents.
- N-heterocyclic carbenes (NHCs) are versatile ligands in coordination chemistry.
- Auto-ionization in metal/metalloid halides is a rare phenomenon.
Purpose of the Study:
- To explore the reactivity of SbF3 in non-polar solvents.
- To investigate the role of NHC ligands in SbF3 auto-ionization.
- To characterize the products of SbF3 reactions with NHCs.
Main Methods:
- Reaction of [SbF3(tmen)] complex with an NHC ligand (L^Dipp).
- Mild heat treatment to induce auto-ionization.
- Spectroscopic and structural analysis of the reaction products.
Main Results:
- Formation of a neutral [(L^Dipp)SbF3] intermediate.
- Unexpected auto-ionization of SbF3 upon heating.
- Rearrangement of the NHC ligand to a mesoionic carbene (MIC).
- Isolation of the auto-ionization product [(L^Dipp)2SbF2]+[SbF4]-.
- Confirmation that tmen acts solely as a solubility enhancer.
Conclusions:
- A novel SbF3 auto-ionization process facilitated by NHC ligand rearrangement has been discovered.
- This study reports the first mesoionic NHC rearrangement on a metal/metalloid fluoride.
- The findings open new avenues for exploring the reactivity of pnictogen halides.
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