Mixed-valence {FeII2FeIII4} hexanuclear complexes with thermally induced Fe(III) spin-crossover behavior
Shuwen Jia1, Lingyue Fan1, Chunyang Zheng2
1Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, Central China Normal University, 430079 Wuhan, P. R. China. dfli@mail.ccnu.edu.cn.
Dalton Transactions (Cambridge, England : 2003)
|August 12, 2022
Summary
New hexanuclear iron complexes were synthesized and characterized. These complexes exhibit temperature-dependent spin-crossover properties, a key characteristic for molecular switches and sensors.
Area of Science:
- Coordination Chemistry
- Materials Science
- Magnetochemistry
Background:
- Mixed-valence iron complexes are of interest for their unique magnetic and electronic properties.
- Spin-crossover (SCO) phenomena in iron complexes enable potential applications in molecular switches and memory devices.
Purpose of the Study:
- To synthesize novel cyano-bridged mixed-valence hexanuclear iron complexes.
- To investigate the structural, magnetic, and spin-crossover properties of these complexes.
Main Methods:
- Synthesis of hexanuclear iron complexes using [Tp4-MeFe(CN)3]- and [Fe(Tpa)]2+ building blocks.
- Single-crystal X-ray diffraction for structural analysis, including single-crystal-to-single-crystal transformations.
- Magnetic susceptibility measurements to determine spin-crossover transition temperatures (T1/2).
Main Results:
- Successful synthesis of three cyano-bridged mixed-valence {Fe6} hexanuclear complexes.
- Complex 1 demonstrated a single-crystal-to-single-crystal transformation in water, yielding a hydroxo-bridged species.
- All synthesized complexes exhibited Fe3+ spin-crossover behavior with transition temperatures ranging from 178 K to 208 K.
Conclusions:
- The study successfully synthesized and characterized novel {Fe6} complexes with tunable SCO properties.
- The findings contribute to the understanding of spin-crossover phenomena in polynuclear iron systems.
- These complexes hold potential for developing advanced functional materials for molecular electronics.
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