Ferromagnetism in polynuclear systems based on non- linear [(Mn2MnIII)-Mn-II] building blocks

The design of new polynuclear transition metal complexes showing large total spin values through parallel alignment of the spins is an important challenge due to the scarcity of bridging ligands that provide ferromagnetic coupling. Herein, we report two new complexes, a [(Mn4Mn2III)-Mn-II] system co...

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Bibliographic Details
Authors: Cirera Fernández, Jordi, Jiang, Yuan, Qin, Lei, Zheng, Yan-Zhen, Li, Guanghua, Wu, Gang, Ruiz Sabín, Eliseo
Format: article
Status:Versión aceptada para publicación
Publication Date:2016
Country:España
Institution:Universidad de Barcelona
Repository:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/154607
Online Access:https://hdl.handle.net/2445/154607
Access Level:Open access
Keyword:Lligands
Propietats magnètiques
Teoria del funcional de densitat
Ferromagnetisme
Ligands
Magnetic properties
Density functionals
Ferromagnetism
Description
Summary:The design of new polynuclear transition metal complexes showing large total spin values through parallel alignment of the spins is an important challenge due to the scarcity of bridging ligands that provide ferromagnetic coupling. Herein, we report two new complexes, a [(Mn4Mn2III)-Mn-II] system containing two non-linear [(Mn2MnIII)-Mn-II] units and a 1D chain system with [(Mn2MnIII)-Mn-II] units that are assembled through dicyanamide bridging ligands coordinated to one of the terminal Mn-II centers. In both cases, the main exchange interaction is between Mn-II center dot center dot center dot Mn-III, showing a relatively strong ferromagnetic coupling. Density functional theory calculations corroborate such ferromagnetic interactions and also provide one magnetostructural correlation, showing that larger Mn-II-O-Mn-III angles enhance the strength of the ferromagnetic coupling. Thus, the non-linear [(Mn2MnIII)-Mn-II] units present in these two complexes are specially suited because of their larger Mn-II-O-Mn-III angles compared to similar previously reported systems containing a linear [(Mn2MnIII)-Mn-II] unit.