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Axially chiral monomeric and dimeric square planar Pd(II) complexes and their application to chiral tectonics
Hisako Sato1, Kazuya Morimoto, Yukie Mori
1Department of Chemistry, Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan. sato.hisako.my@ehime-u.ac.jp
Dalton Transactions (Cambridge, England : 2003)
|March 29, 2013
Summary
Chiral palladium(II) complexes with bis-β-diketonato ligands were synthesized and resolved. These complexes exhibit axial chirality and can form heterometallic structures, opening avenues for new materials.
Area of Science:
- Coordination Chemistry
- Organometallic Chemistry
- Chiral Synthesis
Background:
- Palladium(II) complexes are versatile in catalysis and materials science.
- Chirality in metal complexes is crucial for asymmetric synthesis and molecular recognition.
- Bis-β-diketonato ligands offer unique coordination environments for metal ions.
Purpose of the Study:
- To synthesize and characterize novel mononuclear and dinuclear palladium(II) complexes with bis-β-diketonato ligands.
- To investigate the origin and stability of chirality in these complexes.
- To explore the formation of heterometallic complexes using chiral palladium building blocks.
Main Methods:
- Synthesis of palladium(II) complexes with hexafluoroacetylacetonato (hfac) and various bis-β-diketonato ligands (dabe, baet, dpe).
- Chiral chromatography for optical resolution of palladium(II) complexes.
- Spectroscopic analysis (UV-Vis, CD) and theoretical calculations (TDDFT).
- Formation and characterization of heterometallic tetranuclear iron(III)-palladium(II) complexes.
Main Results:
- Successfully synthesized mononuclear and dinuclear palladium(II) complexes exhibiting axial chirality.
- Achieved stable optical resolution of specific complexes via chiral chromatography.
- Demonstrated that replacing terminal ligands can induce or maintain axial chirality in dinuclear complexes.
- Confirmed the formation of chiral heterometallic tetranuclear complexes [Fe(III){(dbm)Pd(II)(R- or S-baet)}3].
Conclusions:
- The synthesized palladium(II) complexes are stable and exhibit tunable axial chirality.
- Optical resolution is feasible, and the resolved enantiomers are racemization-resistant.
- These chiral palladium complexes serve as valuable building blocks for constructing complex supramolecular architectures and heterometallic compounds.
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