2025-02-252025-02-252024Arias Olivares, N.D., Sánchez de Armas, M.R. y Jiménez Calzado, C. (2024). Guest-dependent Spin Transitions in Hofmann-like FeII SCO Metal-organic Frameworks: Hints from Quantum Chemistry Calculations. Journal of Materials Chemistry C, 12 (37), 14924-14935. https://doi.org/10.1039/D4TC01041H.2050-75342050-7526https://hdl.handle.net/11441/169378The family of 3D Hofmann-like FeII coordination polymers with the formula [Fe(bpd)[MII(CN)4]]·2G, M = Pt, Pd, and Ni is known for having a large capacity to host guest molecules (G) such as nitrobenzene or naphthalene. The presence of the guest molecules modulates the spin-crossover properties. In fact, these clathrates present a large hysteresis loop, in one single step or two well separated steps depending on the guest. In this work, we analyse by means of state-of-the-art DFT-based calculations the main effects governing the occurrence of the multistep spin transition, and the differences due to the nature of the divalent M metal and the encapsulated guest molecules. The study determines the relative stability of the mixed-spin state, the amplitude and nature of the host–guest and guest–guest intermolecular interactions, and the key role played by the C[triple bond, length as m-dash]N stretching modes of the M-cyanide units. Our results provide hints on the distinct roles of each of these factors and how they promote or prevent a direct transition from the high-spin state to the low-spin state.application/pdf12 p.engAttribution-NonCommercial 4.0 Internationalhttp://creativecommons.org/licenses/by-nc/4.0/info:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccess10.1039/D4TC01041H