Exchange interactions on the highest-spin reported molecule: the mixed-valence Fe-42 complex

The finding of high-spin molecules that could behave as conventional magnets has been one of the main challenges in Molecular Magnetism. Here, the exchange interactions, present in the highest-spin molecule published in the literature, Fe-42, have been analysed using theoretical methods based on Den...

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Detalles Bibliográficos
Autores: Aravena Ponce, Daniel Alejandro, Venegas-Yazigi, Diego, Ruiz Sabín, Eliseo
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2016
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/126138
Acceso en línea:https://hdl.handle.net/2445/126138
Access Level:acceso abierto
Palabra clave:Magnetoquímica
Magnetisme
Teoria del funcional de densitat
Espintrònica
Magnetochemistry
Magnetism
Density functionals
Spintronics
Descripción
Sumario:The finding of high-spin molecules that could behave as conventional magnets has been one of the main challenges in Molecular Magnetism. Here, the exchange interactions, present in the highest-spin molecule published in the literature, Fe-42, have been analysed using theoretical methods based on Density Functional Theory. The system with a total spin value S = 45 is formed by 42 iron centres containing 18 high-spin Fe-III ferromagnetically coupled and 24 diamagnetic low-spin Fe-II ions. The bridging ligands between the two paramagnetic centres are two cyanide ligands coordinated to the diamagnetic Fe-II cations. Calculations were performed using either small Fe-4 or Fe-3 models or the whole Fe-42 complex, showing the presence of two different ferromagnetic couplings between the paramagnetic Fe-III centres. Finally, Quantum Monte Carlo simulations for the whole system were carried out in order to compare the experimental and simulated magnetic susceptibility curves from the calculated exchange coupling constants with the experimental one. This comparison allows for the evaluation of the accuracy of different exchange-correlation functionals to reproduce such magnetic properties.