From antiferromagnetic to ferromagnetic exchange in a family of oxime-based Mn(III) dimers: a magneto-structural study

Wdeson P. Barros, Ross Inglis, Gary S. Nichol, Thayalan Rajeshkumar, Gopalan Rajaraman*, Stergios Piligkos, Humberto O. Stumpf, Euan K. Brechin

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

The reaction of Mn(ClO4)(2)center dot 6H(2)O, a derivatised phenolic oxime (R-saoH(2)) and the ligand tris(2-pyridylmethyl)amine (tpa) in a basic alcoholic solution leads to the formation of a family of cluster compounds of general formula [(Mn2O)-O-III(R-sao)(tpa)(2)](ClO4)(2) (1, R = H; 2, R = Me; 3, R = Et; 4, R = Ph). The structure is that of a simple, albeit asymmetric, dimer of two Mn-III ions bridged through one mu-O2- ion and the -N-O- moiety of the phenolic oxime. Magnetometry reveals that the exchange interaction between the two MnIII ions in complexes 1, 3 and 4 is antiferromagnetic, but that for complex 2 is ferromagnetic. A theoretically developed magneto-structural correlation reveals that the dominant structural parameter influencing the sign and magnitude of the pairwise interaction is the dihedral Mn-O-N-Mn (torsion) angle. A linear correlation is found, with the magnitude of J varying significantly as the dihedral angle is altered. As the torsion angle increases the AF exchange decreases, matching the experimentally determined data. DFT calculations reveal that the (dyz)vertical bar pi vertical bar d(yz) interaction decreases as the dihedral angle increases leading to ferromagnetic coupling at larger angles.

Original languageEnglish
Pages (from-to)16510-16517
Number of pages8
JournalDalton Transactions
Volume42
Issue number47
DOIs
Publication statusPublished - 6 Sept 2013

Keywords / Materials (for Non-textual outputs)

  • SINGLE-MOLECULE MAGNETS
  • TRANSITION-METAL-COMPLEXES
  • TARGETED STRUCTURAL DISTORTION
  • THEORETICAL EXPLORATION
  • POLYNUCLEAR COMPLEXES
  • PHYSICAL-PROPERTIES
  • COUPLING-CONSTANTS
  • CRYSTAL-STRUCTURES
  • NI(II) COMPLEXES
  • MN-2(III) DIMER

Fingerprint

Dive into the research topics of 'From antiferromagnetic to ferromagnetic exchange in a family of oxime-based Mn(III) dimers: a magneto-structural study'. Together they form a unique fingerprint.

Cite this