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Trinuclear Mn(II) complex with paramagnetic bridging 1,2,3-dithiazolyl ligands
David J Sullivan1, Rodolphe Clérac, Michael Jennings
1Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada.
Chemical Communications (Cambridge, England)
|October 5, 2012
Summary
Researchers report the first metal coordination complex featuring a radical ligand derived from the 1,2,3-dithiazolyl heterocycle. This novel complex exhibits anti-ferromagnetic coupling between manganese ions and the radical ligand, leading to a unique spin ground state.
Area of Science:
- Coordination Chemistry
- Materials Science
- Organic Synthesis
Background:
- Radical ligands offer unique electronic and magnetic properties.
- 1,2,3-dithiazolyl heterocycles are a relatively unexplored class of organic compounds.
- Metal-radical complexes are of interest for molecular magnetism and spintronics.
Purpose of the Study:
- To synthesize and characterize the first metal coordination complex of a 1,2,3-dithiazolyl-based radical ligand.
- To investigate the magnetic properties of the resulting complex.
- To explore the potential of dithiazolyl heterocycles in coordination chemistry.
Main Methods:
- Synthesis of the 6,7-dimethyl-1,4-dioxo-naphtho[2,3-d][1,2,3]dithiazolyl radical ligand.
- Coordination of the radical ligand with manganese(II) ions using 1,1,1,5,5,5-hexafluoroacetylacetonate (hfac) as a counter-ligand.
- Formation of a volatile, trinuclear complex: Mn(hfac)(2)-Rad-Mn(hfac)(2)-Rad-Mn(hfac)(2).
- Magnetic susceptibility measurements to determine spin coupling and ground state.
Main Results:
- Successful synthesis of the first metal complex incorporating a 1,2,3-dithiazolyl radical ligand.
- The radical ligand acts as a bridging ligand in the trinuclear manganese complex.
- Anti-ferromagnetic (AF) coupling observed between Mn(II) and radical ligand spins.
- An overall spin ground state of S(T) = 13/2 was determined for the complex.
Conclusions:
- This study demonstrates the feasibility of using 1,2,3-dithiazolyl heterocycles as radical ligands in coordination chemistry.
- The observed anti-ferromagnetic coupling highlights the potential for designing novel magnetic materials.
- The volatile nature of the complex may facilitate applications in specific deposition techniques or gas-phase studies.
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