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Updated: May 6, 2026

Frequency and Distribution of Crossovers in Caenorhabditis elegans Meiosis by SNP Genotyping using Real-time PCR
Published on: July 11, 2025
The foundation of modern spin-crossover
1School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, UKLS2 9JT. m.a.halcrow@leeds.ac.uk.
Spin-crossover in iron(II) complexes, first explained in 1966, has driven 50 years of research. This molecular switch phenomenon is key in coordination chemistry, crystal engineering, and nanoscience.
Area of Science:
- Coordination Chemistry
- Solid State Chemistry
- Nanoscience
Background:
- The first explanation of spin-crossover (SCO) in iron(II) complexes was published in 1966.
- SCO complexes act as molecular switches, responding to external stimuli.
- This phenomenon has been extensively studied for nearly five decades.
Purpose of the Study:
- To review the historical development and impact of spin-crossover research.
- To highlight the interdisciplinary nature of SCO studies.
- To underscore the significance of iron(II) complexes as molecular switches.
Main Methods:
- Literature review of research published since 1966.
- Analysis of contributions from coordination chemistry, crystal engineering, solid state chemistry, and physics.
- Examination of applications in nanoscience.
Main Results:
- Spin-crossover research has spanned diverse scientific fields for approximately 50 years.
- Iron(II) complexes exhibiting spin-crossover are a foundational class of molecular switches.
- The study of SCO has fostered significant advancements in multiple scientific disciplines.
Conclusions:
- Spin-crossover in iron(II) complexes represents a pivotal discovery with lasting scientific impact.
- The interdisciplinary research landscape surrounding SCO continues to evolve.
- SCO molecular switches remain a critical area of investigation in modern chemistry and physics.
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