Autor segons l'article: Ghisolfi, A. Monakhov K.Y. Pattacini, R. Braunstein, P. López, X. de Graaf, C. Speldrich, M. van Leusen, J. Schilder, H. Kögerler, P.
Versió de l'article dipositat: info:eu-repo/semantics/acceptedVersion
Departament: Química Física i Inorgànica
URL Document de llicència: https://repositori.urv.cat/ca/proteccio-de-dades/
Resum: We describe the synthesis, structures, and magnetochemistry of new M4Cl4 cubane-type cobalt(II) and nickel(II) complexes with the formula [M(µ3-Cl)Cl(HL·S)]4 (1: M = Co; 2: M = Ni), where HL·S represents a pyridyl-alcohol-type ligand with a thioether functional group, introduced to allow subsequent binding to Au surfaces. Dc and ac magnetic susceptibility data of 1 and 2 were modeled with a full spin Hamiltonian implemented in the computational framework CONDON 2.0. Although both coordination clusters 1 and 2 are isostructural, with each of their transition metal ions in a pseudo-octahedral coordination environment of four Cl atoms and N,O-donor atoms of one chelating HL·S ligand, the substantially different ligand feld effects of Co(II) and Ni(II) results in stark differences in their magnetism. In contrast to compound 1 which exhibits a dominant antiferromagnetic intramolecular coupling (J = -0.14 cm-1), 2 is characterised by a ferromagnetic coupling (J = +10.6 cm-1) and is considered to be a single-molecule magnet (SMM), a feature of special interest for future surface deposition studies. An analysis based on density functional theory (DFT) was performed to explore possible magnetostructural correlations in these compounds. Using a two-J model Hamiltonian, it revealed that compound 1 has four positive and two (small) negative JCo-Co isotropic interactions leading to a SHS = 6 ground state. Taking into account the magnetic anisotropy, one would recover a MS = 0 ground state since D > 0 from computations. In 2, all the J constants are positive and, in this framework, the zero-field splitting energy characterising the axial anisotropy was estimated to with compound 2 being an SMM.
Entitat: Universitat Rovira i Virgili.
Any de publicació de la revista: 2014
Accès a la llicència d'ús: https://creativecommons.org/licenses/by/3.0/es/
ISSN: 1477-9226
Pàgina inicial: 7847
Pàgina final: 7859
Volum de revista: 43
Repositori URV