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Updated: Jan 4, 2026
Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
Published on: July 27, 2022
Proton-Conducting Humidity-Sensitive NiII-NbIV Magnetic Coordination Network
Mateusz Reczyński1, Michał Heczko1, Marcin Kozieł1
1Faculty of Chemistry , Jagiellonian University , Gronostajowa 2 , 30-387 Kraków , Poland.
Abstract:
The 2D coordination network (NH4)2[NiII(cyclam)]3[NbIV(CN)8]2·21H2O (1·21HO) was obtained on a cation-assisted synthetic pathway. The reaction between [Ni(cyclam)]2+ and [Nb(CN)8]4- in the presence of excess of NH4Cl resulted in the formation of negatively charged coordination layers with the simultaneous incorporation of the NH4+ cations into the microporous channels of the structure. 1·21HO network can be partly dehydrated in a single-crystal-to-single-crystal structural transformation to give (NH4)2[NiII(cyclam)]3[NbIV(CN)8]2·14H2O (1·14HO). The dehydration-induced structural changes, in particular the deformation of CN--bridges and the disruption of interlayer interactions, give rise to the solvatomagnetic effect. Fully hydrated 1·21HO phase is a ferrimagnet with a critical temperature of magnetic ordering of 7.6 K and a narrow magnetization hysteresis loop, while 1·14HO hydrate is an antiferromagnet with Tc = 7.2 K and metamagnetic transition at 6.3 kOe. Thanks to the presence of the NH4+ ions in the structure, the proton conductivity of ∼4 × 10-5 S cm-1 (295 K, 100% relative humidity, RH) is observed with the activation energy of 0.80 eV.
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