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A Hydrogen-Bonded Cyanide-Bridged [Co2 Fe2 ] Square Complex Exhibiting a Three-Step Spin Transition
Masayuki Nihei1,2, Yuta Yanai1, I-Jui Hsu3
1Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki, Japan.
Abstract:
Co-crystallization of a cyanide-bridged tetranuclear complex [Co2 Fe2 ] with 4-cyanophenol (CP) gave a hydrogen bonding donor-acceptor system, [Co2 Fe2 (bpy*)4 (CN)6 (tp*)2 ](PF6 )2 ⋅2 CP⋅8 BN (1). 1 exhibited a three-step phase transition between HT, IM1, IM2, and LT phases upon temperature variation. Variable temperature magnetic measurements and structural analyses revealed that the three-step spin transition is caused by electron-transfer-coupled spin transitions (ETCSTs) accompanied with alteration of the hydrogen bonding interactions.
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