Journal Article

FZJ-2015-04175

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png A comparative synthetic, magnetic and theoretical study of functional M$_{4}$Cl $_{4}$ cubane-type Co(ii) and Ni(ii) complexes

Ghisolfi, A. ; Monakhov, K. Y. ; Pattacini, R. ; Braunstein, P. (Corresponding Author) ; López, X. ; de Graaf, C. ; Speldrich, M. ; van Leusen, J. ; Schilder, H. ; Kögerler, P.FZJ*

2014
Soc. London

This record in other databases:      

Please use a persistent id in citations: doi:10.1039/c4dt00306c

Abstract: 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 field 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 JCoCo 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 be negative (D = −0.44 cm−1). The computational results are consistent with compound 2 being an SMM.

---

Contributing Institute(s):

1. Elektronische Eigenschaften (PGI-6)

Research Program(s):

1. 422 - Spin-based and quantum information (POF2-422) (POF2-422)

Appears in the scientific report 2015

---

Database coverage:
; Current Contents - Physical, Chemical and Earth Sciences ; IF < 5 ; JCR ; NCBI Molecular Biology Database ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

---