A spiroborate-based anionic bis-N-heterocyclic carbene.
Jia-Hong Su1, Gene-Hsiang Lee, Shie-Ming Peng
1Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan. cwchiu@ntu.edu.tw.
Dalton Transactions (Cambridge, England : 2003)
|January 8, 2014
Summary
Researchers synthesized a unique twisted bis-benzimidazolium salt. This compound was converted into a spiroborate-linked free bis-N-heterocyclic carbene (bis-NHC) and its diborane adduct and di-rhodium complex.
Area of Science:
- Organometallic Chemistry
- Supramolecular Chemistry
- Carbene Chemistry
Background:
- Benzimidazolium salts are precursors to N-heterocyclic carbenes (NHCs).
- NHCs are versatile ligands in organometallic chemistry.
- Spirocyclic structures offer unique steric and electronic properties.
Purpose of the Study:
- To synthesize and characterize a novel twisted mono-cationic bis-benzimidazolium salt.
- To explore the deprotonation and subsequent transformations of the bis-benzimidazolium salt.
- To generate a spiroborate-linked free bis-NHC and its metal complexes.
Main Methods:
- Dehydrative condensation reaction.
- Deprotonation of benzimidazolium salt.
- Formation of diborane adduct and di-rhodium complex.
Main Results:
- Serendipitous isolation of a twisted mono-cationic bis-benzimidazolium salt.
- Formation of a spiroborate-linked free bis-NHC via deprotonation.
- Successful synthesis of the diborane adduct and a di-rhodium complex.
Conclusions:
- A novel synthetic route to spiroborate-linked bis-NHCs has been established.
- The bis-NHC ligand demonstrates versatility in forming metal complexes.
- The unique twisted structure may influence catalytic activity.
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