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Published on: December 3, 2013
Cooperative spin transition in a mononuclear manganese(III) complex
Paulo N Martinho1, Brendan Gildea, Michelle M Harris
1School of Chemistry & Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland.
Angewandte Chemie (International Ed. in English)
|November 7, 2012
Summary
A mononuclear manganese(III) complex exhibits a complete spin transition with an 8 K hysteresis window. Cooperativity arises from disorder in the counterion, affecting hydrogen-bonded chains and confirming electronic bistability.
Area of Science:
- Materials Science
- Chemistry
- Physics
Background:
- Spin transitions in mononuclear complexes are crucial for molecular switches.
- Understanding cooperativity mechanisms is key to designing advanced materials.
Purpose of the Study:
- To report a complete, cooperative spin transition in a mononuclear Mn(III) complex.
- To elucidate the source of cooperativity in the spin transition.
Main Methods:
- Synthesis and characterization of a mononuclear Mn(III) complex.
- Variable-temperature magnetic susceptibility measurements.
- Single-temperature Raman spectroscopy in warming and cooling modes.
Main Results:
- An 8 K wide hysteresis loop was observed, indicating a complete spin transition.
- Electronic bistability was confirmed within the hysteresis loop via Raman spectroscopy.
- Cooperativity was attributed to disorder in the PF(6)(-) counterion, disrupting 1D hydrogen-bonded chains.
Conclusions:
- A novel cooperative spin transition mechanism was identified in a mononuclear Mn(III) complex.
- The PF(6)(-) counterion's order-disorder transition plays a critical role in spin transition cooperativity.
- This work provides insights into designing molecular materials with tunable spin states.
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