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Magnetic variation induced by structural transformation from coordination chains to layers upon dehydration.
Xiao-Min Liu1, Bao-Ying Wang, Wei Xue
1MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, 510275, PR China.
Dalton Transactions (Cambridge, England : 2003)
|October 11, 2012
Summary
Dehydrating a cobalt coordination polymer with 1,2-di(4H-1,2,4-triazol-4-yl)diazene (bta) transforms it into a layered structure. This structural change induces a magnetic transition from paramagnetic to an antiferromagnetic single-chain magnet.
Area of Science:
- Coordination chemistry
- Materials science
- Magnetism
Background:
- Coordination polymers offer tunable properties based on metal ions and ligands.
- The 1,2-di(4H-1,2,4-triazol-4-yl)diazene (bta) ligand facilitates the formation of extended network structures.
- Investigating the impact of structural transformations on magnetic properties is crucial for developing advanced materials.
Purpose of the Study:
- To synthesize and characterize a novel cobalt-based coordination polymer.
- To explore the structural changes induced by dehydration.
- To investigate the magnetic properties of the resulting coordination polymer phases.
Main Methods:
- Co-precipitation reaction using cobalt bromide, 1,2-di(4H-1,2,4-triazol-4-yl)diazene (bta), and potassium thiocyanate.
- Thermal dehydration at 100 °C.
- Powder X-ray diffraction (PXRD) for structural analysis.
- Magnetic susceptibility measurements.
Main Results:
- A one-dimensional coordination polymer, [Co(SCN)(2)(bta)(H2O)(2)], was synthesized.
- Dehydration yielded a layered coordination polymer, [Co(SCN)(2)(bta)].
- A transition from a paramagnetic to an antiferromagnetic ordered phase was observed, exhibiting single-chain magnet behavior, metamagnetism, and slow magnetic relaxation.
Conclusions:
- The dehydration process significantly alters the structure and magnetic behavior of the cobalt coordination polymer.
- The resulting layered material exhibits single-chain magnet properties, highlighting the potential for stimuli-responsive magnetic materials.
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